HP StorageWorks Storage Mirroring for Linux User’s Guide First Edition (February 2008) Part Number: T2558-96078
© Copyright 2008 Hewlett-Packard Development Company, L.P. Hewlett-Packard Company makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Hewlett-Packard shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.
Table of Contents Preface .........................................................................................................................................i Intended Audience ....................................................................................................................................i Organization of This Guide ......................................................................................................................i Conventions Used in This Guide .................
Chapter 3: Text Clients ...........................................................................................................3-1 The Text Client ........................................................................................................................3-1 Starting the Text Client ........................................................................................................................................................................ 3-1 Using the Text Client .................
Chapter 6: Connections ...........................................................................................................6-1 Connection Options .................................................................................................................6-2 Throughput Diagnostic Utility ................................................................................................6-3 Connection IDs .................................................................................................
Managing Replication Through the Management Console ..................................................8-2 Initiating replication upon connection ............................................................................................................................................... 8-2 Controlling replication manually ......................................................................................................................................................... 8-3 Monitoring replication .....
Chapter 11: Failover ..............................................................................................................11-1 The Failover Process ..............................................................................................................11-1 The Failback Process .............................................................................................................11-1 Failover Terminology ....................................................................................
LogViewer .............................................................................................................................13-32 LogViewer log file ...............................................................................................................................................................................13-33 LogViewer Messages ........................................................................................................................................................
Preface Preface Intended Audience The intended audience for the Storage Mirroring User’s Guide is network administrators with expertise in Linux. The network administrator should be responsible for setup and maintenance of the network and should have working experience installing, configuring, and maintaining network applications. Organization of This Guide Each chapter in this guide is organized in primarily the same manner.
Online References The online manual and online help provide a means of accessing product information. The online help for the Management Console, Failover Control Center, and Text Client are automatically installed with the Storage Mirroring client components. The manuals are also automatically installed. Online help The online help requires a version 4 or later browser (version 4.5 or later is better).
1 X Introduction to Storage Mirroring Introduction to Storage Mirroring Storage Mirroring is a real-time data replication and failover software product. Storage Mirroring augments your existing data protection strategy by reducing downtime and data loss, and it provides these services with minimal impact on existing network and communication resources.
Storage Mirroring Features Storage Mirroring has high availability and disaster recovery management features, resource utilization features, multi-platform features, improved backup benefits, among other features. High availability and disaster recovery management features Continuous, transaction level replication reduces your network’s exposure to data loss by immediately replicating file changes to the target machine.
Storage Mirroring Operations Storage Mirroring performs four basic types of operations: Mirroring—The initial copy or subsequent resynchronization of selected data Replication—The on-going capture of byte-level file changes Failure monitoring and failover—The ability to monitor and stand-in for a machine, in the event of a failure Restoration—A mirror of selected data from the target back to the source Each operation is briefly described in the following sections.
Replication Replication is the real-time transmission of file changes. Unlike other related technologies, which are based on a disk driver or a specific application, the Storage Mirroring replication process operates at the file system level and is able to track file changes independently from the file’s related application. In terms of network resources and time, replicating changes is a more efficient method of maintaining a real-time copy of data than copying an entire file that has changed.
Failure monitoring/failover Failover is a process in which a target machine stands in for a failed source machine. As a result, user and application requests that are directed to the failed source machine are routed to the target machine. Storage Mirroring monitors the status of machines by tracking network requests and responses exchanged between source and target machines. When a monitored machine misses a user-defined number of requests, Storage Mirroring assumes that the machine has failed.
Restoration Restoration provides an easy method for copying replicated data from the target back to its original location on the source. The process only requires you to select the source, target, and the appropriate replication set. There is no need to select files or to remember where the data came from on the source since that information is maintained by Storage Mirroring.
Sample Configurations Storage Mirroring is an exceptionally flexible product that can be used in a wide variety of network configurations. To implement Storage Mirroring effectively, it is important to understand the possible configuration options and their relative benefits. Storage Mirroring configuration options can be used independently or in varying combinations. NOTE: Storage Mirroring’s replication and failover features have different machine requirements.
One-to-One, Active/Active Replicated Data 1 Source Data 1 Source Data 2 Replicated Data 2 Target and Source Machine (Active) Source and Target Machine (Active) Description Each machine acts as both a source and target actively replicating data to each other. Applications This configuration is appropriate for failover and critical data backup. This configuration is more cost-effective than the Active/Standby configuration because there is no need to buy a dedicated target machine for each source.
Many-to-One Source Machine Source Machine Source Machine Target Machine Description Many source machines are protected by one target machine. Application This configuration is appropriate for offsite disaster recovery. This is also an excellent choice for providing centralized tape backup because it spreads the cost of one target machine among many source machines. Considerations The target machine must be carefully managed.
One-to-Many Source Machine Target Machine Target Machine Target Machine Description One source machine sends data to multiple target machines. The target machines may or may not be accessible by one another. Applications This configuration provides offsite disaster recovery, redundant backups, and data distribution. For example, this configuration can replicate all data to a local target machine and separately replicate a subset of the mission-critical data to an offsite disaster recovery machine.
Chained Source Machine Target and Source Target Machine Machine Description One or more source machines sends replicated data to a target machine that in turn acts as a source machine and sends selected data to a final target machine which is often offsite. Applications This is a convenient approach for integrating local high availability with offsite disaster recovery. This configuration moves the processing burden of WAN communications from the source machine to the target/source machine.
Single Machine /Data /Data Replication Set Data Copy of Replication Set on Specified Target Path Source and Target Machine Description Source and target Storage Mirroring components are loaded on the same machine allowing data to be replicated from one location to another on the same volume or to a separate volume on the same machine. Applications This configuration is useful for relocating data within existing machines so that open files can be backed up.
2 X Management Console Management Console The Management Console is a 32-bit, Microsoft® Windows® GUI client that can manage and monitor Storage Mirroring components. Storage Mirroring machines are displayed along with active connection information. NOTE: You may not have access to some of the components or see certain display options if you are using a newer version of the Management Console to control an older version of your source or target.
Understanding the Display The left pane is a tree view displaying each machine running Storage Mirroring. As each machine name is highlighted, note the following items: The status bar at the top of the pane displays the modules loaded on each machine: Source, Target, Source and Target, or None. (None indicates that the core functionality of Storage Mirroring is running, but neither the source nor target modules have been loaded.
The right pane displays the following information depending on the item selected in the left pane of the Management Console and the tab selected on the right pane. Right Pane Icons Left Pane Right Pane Description World View No Tabs All connected machines and their current connection state are displayed. Source Machine Source Tab The active connections, if any, from that source machine are displayed. Source Machine Target Tab The display is blank.
Management Console toolbar The following icons appear in the Management Console toolbar.
Logging On and Off of Storage Mirroring To ensure protection of your data, Storage Mirroring offers multi-level security using native operating system security features. Privileges are granted through membership in user groups defined on each machine running Storage Mirroring. To gain access to a particular Storage Mirroring source or target, the user must provide a valid operating system user name and password and the specified user name must be a member of one of the Storage Mirroring security groups.
Storage Mirroring Ports Both the Management Console and the Storage Mirroring server use ports to communicate with each other. Management Console ports The Storage Mirroring Management Console uses two ports for Storage Mirroring communications. Heartbeat Port—The Management Console uses this port to listen for heartbeats transmitted from Storage Mirroring servers.
Storage Mirroring server ports The Storage Mirroring daemon uses three ports for Storage Mirroring communications. Service Listen Port—The Storage Mirroring server uses this port to listen for commands from other Storage Mirroring servers. Heartbeat Transmit Port—The Storage Mirroring server uses this port to transmit heartbeats. Status Listen Port—The Storage Mirroring server uses this port to listen for requests to update at-a-glance monitoring from the Storage Mirroring Management Console. 1.
Inserting a Server If a machine is not displayed on the Management Console, it can be manually inserted. This feature is useful for machines that are across a router or on a different network segment. These types of machines will not automatically appear in the Management Console because the UDP heartbeat is not passed by the router.
Storage Mirroring Workspaces The Management Console workspace contains the display of the panes of the Management Console and any servers that may have been inserted. Multiple workspaces can be used to help organize your environment or to view settings from another machine. Saving a workspace As you size, add, or remove windows in the Management Console, you can save the workspace to use later or use on another Storage Mirroring client machine.
3 X Text Clients Text Clients The Double-Take Command Language (DTCL) is a scripting language that can be used in either the Text Client or Command Line Client to manage and monitor Storage Mirroring components. It can also be used in script files to execute series and combinations of commands to meet specific needs. Because the Text Client and Command Line Client use the same DTCL commands, all examples use the Text Client.
The Command Line Client The Command Line Client can be run from a command prompt. It can manage and monitor Storage Mirroring components on any platform regardless of the Command Line Client platform. The Command Line Client is run from the operating system command line and the DTCL commands are run from the Storage Mirroring command line.
Logging on and off of Storage Mirroring To ensure protection of your data, Storage Mirroring uses native operating system security and requires a valid system username and password. If you do not have a valid system username and password for a selected machine, you will not be able to configure Storage Mirroring for that machine. As you enter DTCL commands, Storage Mirroring automatically attempts to log on to the source or target machine. You can verify your access by the resulting message.
Examples logout indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Stopping the Daemon To stop the Storage Mirroring daemon from the Text Client, use the shutdown command. Command SHUTDOWN Description Stops the Storage Mirroring daemon Syntax SHUTDOWN Options machine—Name of the machine Examples shutdown indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Specifying Source and Target Functionality If you did not specify your machine as a source or target when starting the Storage Mirroring you will need to load the modules using the DTCL commands load source or load target. Command LOAD SOURCE Description Loads the Storage Mirroring source module Syntax LOAD SOURCE Options machine—Name of the machine Examples load source indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Storage Mirroring Ports Both the text clients and the Storage Mirroring server use ports to communicate with each other. Text client ports The Storage Mirroring text clients use two ports for Storage Mirroring communications. netport—The text clients use this port to send commands to a Storage Mirroring server. unetport—The text clients use this port to listen for heartbeats sent from a Storage Mirroring server. 1.
Notes Some settings, although immediately applied to Storage Mirroring, will not take effect until the client or daemon is restarted. For example, the Text Client must be closed and reopened for a change to ClientLogName to take effect. And the daemon must be restarted to cause a change in the modules loaded if the LoadSourceTarget setting is changed. See Storage Mirroring Text Client program settings on page 14-11 for details on each configuration option.
Storage Mirroring server ports The Storage Mirroring daemon uses two ports for Storage Mirroring communications. netport—The Storage Mirroring server uses this port to listen for commands from a Storage Mirroring text client. unetport—The Storage Mirroring server uses this port to send heartbeats to Storage Mirroring clients. 1. To determine the current netport setting on a Storage Mirroring server, use the get command with the netport option. The default port number is 1500.
Getting Help in the Text Clients A listing of the DTCL commands and their syntax is available in the Storage Mirroring Text Client and Command Line Client by typing the help command. Command HELP Description Displays the DTCL commands and their syntax Syntax HELP Notes Press any key to scroll through the list of commands. Press q to exit the help function. You can also type DTCL help to display the DTCL commands and their syntax.
4 X Failover Control Center Failover Control Center The Storage Mirroring Failover Control Center is a 32-bit Windows client that controls all aspects of Storage Mirroring failover. It configures the failover settings, control the failover processes, and monitor the status of failover activity. For detailed steps on how failover works including configuring and monitoring failover, see Failover on page 11-1.
Understanding the Display The Failover Control Center’s main window controls three types of failover activities: Identifying what the target is monitoring Configuring failover operations Monitoring failover activity Identifying what the target is monitoring The two main areas of the Control Center screen are the Target Machine selection and the Monitored Machines/Names pane.
Monitoring failover Now that replication and failover monitoring are configured and started, you will need to know if and when there is a problem. Since it can be essential to quickly know the status of your machines, Storage Mirroring offers various methods for monitoring the status of failover.
The following table identifies how the visual indicators change as the status of failover changes. Time to Fail Countdown Source is Online Source Fails and Failover is Initiated Failover is Complete Status Bar Colored Bullets Desktop Icon Tray The Time to Fail counter is counting down and resetting each time a heartbeat is received from the source machine. The status bar indicates that the target machine is monitoring the source machine. The bullets are green.
Communication ports The Storage Mirroring daemon and the Failover Control Center use two ports for various Storage Mirroring communications. Service Transmit Port—The Failover Control Center uses this port to send commands to Storage Mirroring servers. Heartbeat Listen Port—The Failover Control Center uses this port to listen for heartbeats transmitted from Storage Mirroring servers. To view or modify the port settings in the Failover Control Center, select Settings, Communications.
5 X Replication Sets Replication Sets A replication set defines the data on a source machine that is to be protected by Storage Mirroring. Replication sets are defined by the volumes, directories, files, or wild card combinations that are to be replicated to the target. Creating multiple replication sets allows you to customize sets of data that need to be protected. Replication Set Rules Replication sets are created by defining rules.
If a soft link to a directory is part of a replication set rule’s path above the entry point to the replication set data, that link will be created on the target as a regular directory if it must be created as part of the target path.
Replication Set Operations The following replication set operations are available: Create—You can create replication sets through the Management Console or the text clients by selecting icons through the graphical interface or by specifying explicit paths through any of the clients. Modify—Replication set modifications are a dynamic process. While Storage Mirroring is replicating, changes can be made to a replication set that is in use.
Managing Replication Sets Through the Management Console The following sections describe how to manage replication sets through the Storage Mirroring Management Console. Each section assumes that you have already logged into the source machine. Creating a replication set 1. You can use either of the following methods to create a new replication set when a source machine is highlighted: Select Insert, Replication Set from the menu bar.
3. To see the directory tree for the source machine selected, expand and collapse the directory structure in the left pane of the Management Console by clicking on a box containing a plus sign to expand the tree and a box containing a minus sign to collapse the tree. NOTE: 4. Define the data to be protected by selecting volumes, drives, directories, and/or specific files by marking the check box next to the desired selection. NOTE: 5.
Creating a replication set using wild cards and direct rule entry In some instances, data may need to be replicated that cannot be easily selected from the Management Console, or the directories or files may not exist. For example, Storage Mirroring’s wild card capabilities and flexible file selection process allows you to manually include all .db files from a specific directory that is otherwise excluded. This flexibility is available through the Replication Set Properties dialog box. 1.
Calculating replication set size While Storage Mirroring is mirroring, the right pane of the Management Console displays statistics to keep you informed of its progress. If the size of the replication set is determined before the mirror is started, Storage Mirroring can display the percentage of the replication set that has been mirrored in the Mirror Status column. If the size was not calculated prior to starting the mirror, the column displays Mirroring.
Modifying a replication set Storage Mirroring allows you to make modifications to a replication set when you want to change the data you wish to protect. This allows you to add, remove, or modify any replication set rules without having to create a new replication set. 1. In the left pane, highlight the replication set you want to modify and expand the volume and directory levels as needed. 2.
Managing Replication Sets Through the Text Client The following sections describe how to manage replication sets through the Storage Mirroring text clients. For a complete list of the DTCL commands, see Storage Mirroring Commands on page A-1. Each of the following commands assumes that you have already logged on and identified a source machine. Creating a replication set 1. Use the repset create command to create a new replication set.
3. Define a replication set rule by using the repset rule add command. Command REPSET RULE ADD Description Adds a rule to a replication set. A rule is the specification of a path including volume, directories, wild cards, and/or file names.
Calculating replication set size While Storage Mirroring is mirroring, the Text Client displays statistics to keep you informed of its progress. If the size of the replication set is determined before the mirror is started, Storage Mirroring can display the percentage of the replication set that has been mirrored. If the size was not calculated prior to starting the mirror, it displays Mirroring. You can calculate the replication set size manually or on connection. 1.
b. To modify whether or not the replication set size will be calculated when the connection is established, use the set command with the CalculateOnConnect option. The CalculateOnConnect option is set to 1 for enabled or 0 for disabled. By default, the replication set size will be calculated. Command SET Description The Text Client/DTCL sends a request to Storage Mirroring to modify the value of a Storage Mirroring program setting.
Modifying a replication set Make modifications to a replication set when you want to change the data you wish to protect. 1. View the replication sets associated with the active source machine by using the repset list command. Command REPSET LIST Description Lists all replication set names for the currently selected source Syntax REPSET LIST Storage Mirroring version 4.
Storage Mirroring version 4.3 Source Machine: indy (Access Level: FULL) Replication Set: Customer Data /var/spool /var/spool/CustomerDB *Modified* exclude recursive include recursive (press any key) > repset display 4. Remove the existing rule that you need to change using the repset rule remove command.
5. Add a new rule by using the repset rule add command. Command REPSET RULE ADD Description Adds a rule to a replication set. A rule is the specification of a path including volume, directories, wild cards, and/or file names. Syntax REPSET RULE ADD [INCLUDE|EXCLUDE][, RECURSIVE|NONRECURSIVE][TO ] Options 6.
Deleting a replication set 1. View the replication sets associated with the active source machine by using the repset list command. Command REPSET LIST Description Lists all replication set names for the currently selected source Syntax REPSET LIST Storage Mirroring version 4.3 Source Machine: indy - List of rep sets Customer Data (press any key) (Access Level: FULL) * DATABASE HAS BEEN MODIFIED * disabled > repset list 2. 3. Delete the replication set by using the repset delete command.
6 X Connections Connections The Storage Mirroring connection is the link between the source replication set and a target machine. It is a logical connection and refers to the relationship between the replication set on the source and the copy of the data on the target, as well as the status of the connection. The different connection states are described below. Connection Status Description Started The network connection exists and is available for data transmission.
Connection Options When establishing a connection, you must specify the machines that are involved with the connection, what data is being protected and where that data is going, as well as configuring how this connection will perform. Source Server—You must specify the Storage Mirroring source machine that contains the replication set that is going to be transmitted to the Storage Mirroring target.
Throughput Diagnostic Utility Built into Storage Mirroring is a null, or non-existent, target that allows you to imitate a normal connection without passing any data across the network. The purpose of this connection is to generate statistics that can be used in approximating the time and amount of bandwidth that this connection will use when actively established. The name of the target is TDU or Throughput Diagnostics Utility. The statistics are logged to a file. By default, the file is called statistic.
Queuing Queuing to disk allows Storage Mirroring to accommodate high volume processing that might otherwise fill up system memory. For example, on the source, this may occur if the data is changing faster than it can be transmitted to the target or on the target, a locked file might cause processing to backup. The following diagram will help you understand how queuing works. Each numbered step is described after the diagram.
Auto-Disconnect and Auto-Reconnect While disk queues are user configurable and can be extensive, they are limited by the amount of physical disk space available. If the amount of disk space specified for disk queuing is met, additional data could not be added to the queue and data would be lost. To avoid any data loss, the auto-disconnect and auto-reconnect processes occur. Source—If disk queuing is exhausted on the source, Storage Mirroring will automatically start disconnecting connections.
Managing Connections Through the Management Console The Management Console can be used to establish, disconnect, and monitor a connection between the source replication set and a target machine. In addition, the Management Console can be used to configure queuing and auto-reconnect.
5. Select the target path, which corresponds to the desired location on the target where the replicated data will reside, by selecting One-to-One or All-to-One. If you want to specify a custom location, select either of the radio buttons and then click on the directory entry under the Target Path column. You will be in edit mode and can specify the desired location on the target for the replicated data. 6.
Monitoring a connection You can monitor an established Storage Mirroring connection by viewing the connection statistics and/or the connection display. These are not the only methods available for monitoring an established Storage Mirroring connection. For information on all of the monitoring methods, see Monitoring Tools on page 13-1. Connection statistics 1.
Connection display You can monitor the connection by understanding the different icons displayed in the Management Console. Established Connection Status Icon—The source/target connection status appears as an icon to the left of the replication set name. (If you have reordered the connection data items displayed, the icon will appear to the left of the first column that is displayed.
Configuring queuing There are five queuing parameters available for configuration. 1. Right-click a source machine and select Properties. 2. Select the Queue tab. 3. Specify the Folder which will store the queue. By default, this is /var/run/StorageWorks/StorageMirroring. 4. Specify the Maximum system memory for queue. This is the amount of system memory, in MB, that, when exceeded, will trigger queuing to disk.
Configuring auto-reconnect If Storage Mirroring is stopped on a source machine while a Storage Mirroring connection is active, auto-reconnect will automatically reestablish the connection, without manual intervention by the administrator, when the Storage Mirroring source is available. When an auto-reconnect is performed, you may want to perform an auto-remirror to guarantee data integrity. Use the instructions below for both the auto-reconnect and auto-remirror options. 1.
Managing Connections Through the Text Client For each of the connection related commands, first identify which source you are working with by using the source command. Command SOURCE Description Identifies a machine as the active source machine Syntax SOURCE Options source_machine—Name of the machine Examples source indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Establishing a new connection 1.
Options repset—Name of the replication set target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP address MAP EXACT—Specifies that the replication set data will be sent to the same logical volume on the MAP BASE—The replication set data will be sent to the locations specified below: target connect repset to target—If mappings are not specified with the command, map base will be used by default.
Connecting to the Throughput Diagnostics Utility To initiate a connection to the Throughput Diagnostics Utility, use the connect to tdu command. This logs the connection statistics to the file specified. The remaining connection flags are identical to the standard connect command.
Monitoring a connection Storage Mirroring offers a variety of methods for monitoring a Storage Mirroring connection. Statistics include information like connection up-time, target status, bytes queued or sent, etc. The informational data includes processing notifications, warnings or errors. Below is a brief description of how four of the monitoring methods are applicable to the Storage Mirroring connection. For detailed information on these and other monitoring methods, see Monitoring Tools on page 13-1.
Configuring queuing There are five queuing parameters available for configuration. Use the get and set commands to view or modify an option. See Storage Mirroring Commands on page A-1 for complete command syntax. QJournalDir—This is the location where the queue is stored. QJournalFileSize—This is the size, in MB, of each queuing transaction log file. By default, the file size is 5 MB. QmemoryBufferMax—This is the amount of system memory, in MB, that, when exceeded, will trigger queuing to disk.
2. To modify the auto-reconnect setting, use the set command with the AutoReconnect option. The AutoReconnect option is set to 1 for enabled or 0 for disabled. By default, auto-reconnect is enabled. Command SET Description The Text Client/DTCL sends a request to Storage Mirroring to modify the value of a Storage Mirroring program setting. The setting is immediately applied and is then forwarded to the registry where it is also applied.
7 X Mirroring Mirroring Mirroring is the process of transmitting the data contained in a replication set from the source to the target machine so that an identical copy of data exists on the target machine. All file and security attributes are also mirrored to the target machine. Mirroring must occur initially to generate a baseline copy from the source to the target. After mirroring has occurred, replication maintains an identical copy of the data on the target.
File Differences Mirror Options Block Checksum File Differences Only if Source is All Server Newer Mirroring Properties Source Mirroring Option Taba Option (3) (3) Block Checksum Mirroring Option 3 Any file that is different on the source and target based on the date, time, and/or size is transmitted to the target. The mirror sends the entire file. 3 Any file that is newer on the source than on the target based on date and/or time is transmitted to the target. The mirror sends the entire file.
Stopping and Pausing Mirroring While a mirror is in progress, you can manually stop or pause the transmission of data to the target. The Storage Mirroring connection will remain intact and the mirror data may or may not queue on the source depending on the option you choose. Pause and Resume—When pausing a mirror, Storage Mirroring stops queuing mirror data on the source but maintains a pointer to determine what information still needs to be mirrored to the target.
Auto-Remirror When a source machine fails, the auto-reconnect feature will reestablish the source/target connection when the source is back online. The auto-remirror option will then initiate the mirror process to synchronize the files on the source and target machines. For more information on source machine failures, see . When a target machine fails, the Storage Mirroring source maintains the source/target connection and queues replication data.
How Mirroring Works To better understand how Storage Mirroring mirroring works, the following diagram identifies the different steps that are completed when a mirror is performed. Each numbered step is described below the diagram. 1 Files Contained In Replication Set Identical Copy Of Replication Set 3 2 4 Source Target 1. Mirroring is initiated by the user, either manually through one of the clients or automatically when the connection is created. 2.
Managing Mirroring Using the Management Console Through the Management Console, a mirror can be initiated upon connection, manually controlled, and monitored. In addition, the Management Console can be used to configure orphan files and to automatically run an auto-remirror after an auto-reconnect to ensure that data is identical on the source and target. Initiating a mirror upon connection 1.
Controlling a mirror manually After a connection is established you can manually start, stop, pause, or resume mirroring. Right-click the connection on the right pane of the Management Console and select Mirroring and the appropriate mirror control. Start—If you select to start a mirror, you will need to make the following two selections on the Start Mirror dialog box: Type of Mirror—Specify the type of mirror, Full or File Differences, you wish to perform.
Monitoring a mirror 1. To view the connection on the Management Console, highlight the source machine on the left pane and the connection will appear on the right pane. Use the horizontal scroll bar at the bottom of the right pane to view the Mirror Status column; the status of the mirroring operation for this connection is displayed. The possible states are: Idle— No mirroring activity is taking place.
Configuring orphan files 1. You can configure orphan files when establishing a connection or after a connection has been created. If you have not yet established a connection, follow the procedures as described in insert cross reference. If you want to configure the orphan files setting on an established connection, right-click the connection on the right pane of the Management Console and select Connection Manager.
Setting auto-remirror In the event of a source machine failure or if the Storage Mirroring daemon stops, data integrity between the source and target cannot be guaranteed. To resolve this issue, the Storage Mirroring auto-reconnect process automatically reestablishes any source/target connections that existed prior to Storage Mirroring being unavailable. After an auto-reconnect, an auto-remirror will ensure that data is identical on the source and target machines.
Managing Mirroring Using the Text Client For each of the mirroring commands, first identify which source you are working with by using the source command. Command SOURCE Description Identifies a machine as the active source machine Syntax SOURCE Options source_machine—Name of the machine Examples source indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Initiating a mirror on connection 1. 2.
Options repset—Name of the replication set target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP address MAP EXACT—Specifies that the replication set data will be sent to the same logical volume on the MAP BASE—The replication set data will be sent to the locations specified below: target connect repset to target—If mappings are not specified with the command, map base will be used by default.
Controlling a mirror manually Identify the connection ID by locating the number in the left column below the target machine name and use one of the following commands for the appropriate mirror control: Mirror Stop Command MIRROR STOP Description Stops a paused mirror Syntax MIRROR STOP Options con_id—Connection ID assigned to the source/target connection *—Specifies all connection IDs mirror stop 1 mirror stop * Examples Mirror Start Command MIRROR START Descri
Mirror Pause Command MIRROR PAUSE Description Pauses a mirror that is in progress Syntax MIRROR PAUSE Options con_id—Connection ID assigned to the source/target connection *—Specifies all connection IDs. mirror pause 1 mirror pause * Examples Mirror Resume Command MIRROR RESUME Description Resumes a paused mirror Syntax MIRROR RESUME Options con_id—Connection ID assigned to the source/target connection *—Specifies all connection IDs.
Monitoring a mirror Storage Mirroring offers a variety of methods for monitoring Storage Mirroring mirroring. Statistics include information like connection up-time, target status, bytes queued or sent, and so on. The informational data includes processing notifications, warnings or errors. Below is a brief description of how four of the monitoring methods are applicable to the Storage Mirroring connection. For detailed information on these and other monitoring methods, see Monitoring Tools on page 13-1.
Configuring orphan files 1. To determine the current orphan files setting, use the get command with the MoveOrphanedFiles option. By default, orphan files are not deleted. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
6. To modify the location of renamed orphan files, use the set command with the MoveOrphansDir option. This option accepts any valid directory. By default, the directory /var/lib/StorageWorks/StorageMirroring. NOTE: If you are moving files, make sure the directory you specify to move the files to is not included in the destination of the replication set data so that the orphan files are only moved once. 7.
Setting auto-remirror In the event of a source machine failure or if the Storage Mirroring daemon stops, data integrity between the source and target cannot be guaranteed. To resolve this issue, the Storage Mirroring auto-reconnect process automatically reestablishes any source/target connections that existed prior to Storage Mirroring being unavailable. After an auto-reconnect, an auto-remirror will ensure that data is identical on the source and target machines.
8 X Replication Replication A file change, also called a file request or operation, is the creation, modification, or deletion of a file. This also includes file attribute and permission changes. Replication is the real-time transmission of these file changes as they occur. The file changes are replicated from the source to the target, maintaining an identical copy of data on the target machine.
Managing Replication Through the Management Console Using the Management Console, replication can be initiated upon connection, manually controlled, and monitored. In addition, task commands can be inserted in the replication queue. Initiating replication upon connection 1. There are four methods available for establishing a connection and opening the Connection Manager: Highlight a replication set and select Tools, Connection Manager. Right-click on a replication set and select Connection Manager.
Controlling replication manually To stop and start replication for an established source/target connection, right-click the connection on the right pane of the Management Console and select Replication and the appropriate replication control. NOTE: If you stop replication manually, you will need to perform a remirror when it is restarted. If you only need to temporarily pause data from being transmitted to the target and do not want to stop replication, select Transmit, Pause.
Processing task commands Task command processing is a Storage Mirroring feature that allows you to insert and run tasks at various points during the replication of data. Because the tasks are user-defined, you can achieve a wide variety of goals with this feature. For example, you might insert a task to create a snapshot or backup on the target after a certain segment of data from the source has been applied on the target. 1. To process a task, you must first enable task command processing.
Managing Replication Through the Text Client For each of the replication commands, first identify which source you are working with by using the source command. Command SOURCE Description Identifies a machine as the active source machine Syntax SOURCE Options source_machine—Name of the machine Examples source indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Initiating replication on connection 1. 2.
Options repset—Name of the replication set target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP address MAP EXACT—Specifies that the replication set data will be sent to the same logical volume on the MAP BASE—The replication set data will be sent to the locations specified below: target connect repset to target—If mappings are not specified with the command, map base will be used by default.
Controlling replication manually Identify the connection ID by locating the number in the left column below the target machine name and use one of the following commands for the appropriate replication control: Replication Start Command REPLICATION START Description Initiates the replication process Syntax REPLICATION START Options conid—Connection ID assigned to the source/target connection *—Specifies all connection IDs replication start 1 replication start * Examples
Monitoring replication Storage Mirroring offers a variety of methods for monitoring Storage Mirroring mirroring. Statistics include information like connection up-time, target status, bytes queued or sent, and so on. The informational data includes processing notifications, warnings or errors. Below is a brief description of how four of the monitoring methods are applicable to the Storage Mirroring connection. For detailed information on these and other monitoring methods, see Monitoring Tools on page 13-1.
Processing task commands Task command processing is a Storage Mirroring feature that allows you to insert and run tasks at various points during the replication of data. Because the tasks are user-defined, you can achieve a wide variety of goals with this feature. For example, you might insert a task to create a snapshot or backup on the target after a certain segment of data from the source has been applied on the target. To process a task, enable task command processing and then use the queuetask command.
4. Use the queuetask command to places task(s) in the replication queue inline with current processing. Command QUEUETASK Description Queues tasks inline with replication data. Syntax QUEUETASK TO ONQUEUE = [args] | ONTRANSMIT = [args] | ONRECEIVE = [args] | ONEXECUTE = [args] [TIMEOUT = ] [INTERACT | NOINTERACT] Options job_name—Any name that you have assigned to the job.
Notes The default setting for this command is nointeract. Any combination of one or more execution points can be used with the same queuetask command. Options that contain non-alphanumeric characters must be enclosed in quotation marks. All processing messages, including errors, can be viewed in the Storage Mirroring logs and the Linux system log.
9 X Verification Verification Verification is the process of confirming that the data on the target is identical to the data on the source. Verification creates a log file detailing what was verified as well as which files are not synchronized. If the data is not the same, Storage Mirroring can automatically initiate a remirror. The remirror ensures data integrity between the source and target.
Remirror Options When Verifying Block Checksum Remirror All Server Automatical Properties Source ly Verify Option Taba (3) (3) 3 (3) Only if Source is Newer Verify Option Block Checksum Verify Option Action Performed 3 Any file that is different on the source and target based on the date, time, and/or size is transmitted to the target. The mirror sends the entire file. 3 Any file that is newer on the source than on the target based on date and/or time is transmitted to the target.
Verification Log A verification log is created on the source during the verification process. The log identifies what is verified as well as which files are not synchronized. The options and defaults are listed below. File Name and Location—By default, the verification log is called DTVerify.log and is stored in /var/log/StorageWorks/StorageMirroring. Append or Overwrite—By default, the log is appended each time a verification process is completed.
How Verification Works To better understand how Storage Mirroring verification works, the following diagram identifies the steps involved with the Storage Mirroring verification process. Each numbered step is described below the diagram. 1 Files Contained In Replication Set Replicated Files 4 2 5 3 Source Target Verification Log 1. Verification is initiated by the Storage Mirroring administrator, either manually through one of the clients or automatically through a scheduled verify. 2.
Managing Verification With the Management Console In the Management Console, verification can be configured when a connection is established or it can be initiated manually at any time while a connection is active. Configuring verification on connection 1. There are four methods available for establishing a connection and opening the Connection Manager: Highlight a replication set and select Tools, Connection Manager. Right-click on a replication set and select Connection Manager.
Initiating verification manually 1. To initiate verification manually, right-click the connection on the right pane of the Management Console and select Verify. 2. Select the verification options that you would like to perform. Verify Only—This option performs the verification process by comparing the date, time and size of each file and generates a verification report identifying the files that are not synchronized.
Verification log A verification log is created during the verification process. The log details what is verified as well as which files are not synchronized. Use the following steps to set up your verification log in the Management Console. NOTE: All changes to a verification log should be made on the source side of a connection. 1. Right-click a source machine on the left pane of the Management Console and select Properties. 2. Select the Logging tab. 3.
Monitoring verification To view the connection on the Management Console, highlight the source machine on the left pane and the connection will appear on the right pane. Use the horizontal scroll bar at the bottom of the right pane to view the Mirror Status column; the status of the mirroring operation for this connection is displayed. The possible states are Idle— No mirroring or verifying activity is taking place.
Managing Verification Using the Text Client In the Storage Mirroring Text Client, verification can only be initiated after a connection is established. Initiating verification 1. Log on to the source using the login command. Command LOGIN Description Log on to a Storage Mirroring machine Syntax LOGIN [domain] Options machine—Name of the machine username—Name of the user password—Password associated with username.
3. Identify the connection ID by locating the number in the left column below the target machine name and initiate the verification process by using the verify command. Command VERIFY Description Verifies the integrity of the data between the source and target machines.
Setting the verification log attributes 1. To determine the current status of the verification log, use the get command with the VerifyLogName option. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Notes Some settings, although immediately applied to Storage Mirroring, will not take effect until the client or daemon is restarted. For example, the Text Client must be closed and reopened for a change to ClientLogName to take effect. And the daemon must be restarted to cause a change in the modules loaded if the LoadSourceTarget setting is changed. See Storage Mirroring Text Client program settings on page 14-11 for details on each configuration option.
10 X Data Transmission Data Transmission Storage Mirroring’s replication and mirroring processes place replication set data on queues on the source and the transmission process sends the data from the source to the target. There are three methods for transmitting the Storage Mirroring data: Real-time transmission—Storage Mirroring data is continuously transmitted to the target machine.
Scheduled Transmission Options The following transmission options are available through the Management Console and the Text Clients. They are user configurable settings which can occur in any order or combination. The options can be set and then disabled, allowing you to enable them only when you need to use them. NOTE: The transmission options are set for each target machine and cannot be defined separately for each replication set or source/target combination.
Setting a Storage Mirroring Transmission Window—The transmission window establishes a period of availability for all Storage Mirroring transmissions. You can specify a begin and end time for all Storage Mirroring transmissions. When a transmission window is in effect, all other start and stop criteria are bound by this window. This means that Storage Mirroring will never transmit data outside of an established window, regardless of other transmission settings.
Setting bandwidth limitations 1. Select the Bandwidth option in the Limit Type box. 2. Mark the Limit Bandwidth check box to enable the bandwidth limiting features. 3. Define the bandwidth available for Storage Mirroring transmission by using either of the following options: Percentage—Specify the percentage of bandwidth to be used for Storage Mirroring transmissions and the total bandwidth capacity that is available. 4.
Setting transmission start criteria Transmission start criteria initiates Storage Mirroring data transmission which continues until the queue is empty or a transmission stop criteria is met. 1. Select the Start option in the Limit Type box. 2. Define the start options for Storage Mirroring transmission by using any combination of the following options: Transmission session start—Specify a Date and Time to start transmitting data.
Setting transmission stop criteria Transmission stop criteria stops Storage Mirroring data transmission after a transmission start criteria has initiated the transmission. If a stop criteria has not been established, the transmission will end when the queue is empty. 1. Select the Stop option in the Limit Type box. 2.
Setting a transmission window The transmission window establishes a period of availability for all Storage Mirroring transmissions. NOTE: Setting a transmission window by itself is not sufficient to start a transmission. You still need to set a start criteria. 1. Select the Window option in the Limit Type box. 2. Mark the Enable Transmission Window check box to enable the transmission window feature. 3.
Controlling transmission manually To start, stop, pause, or resume the transmission of data from the source to the target, right-click an established connection and select Transmit and the appropriate transmission control.
Setting Transmission Criteria Using the Text Client The Text Client uses the schedule commands to establish scheduled transmission criteria. To control transmission manually using the Text Client, the transmission command can be used with the stop, start, pause, or resume switches. Configuring transmission criteria before establishing a connection After you have specified the source you are working with, establish scheduled transmission criteria using the following various schedule commands.
Setting bandwidth limitations Set the bandwidth by using the limit bandwidth command.
Setting transmission stop criteria Specify any of the following options to stop transmitting Storage Mirroring data to the target machine. Specifying Transmission Duration—Specify the maximum length of time that Storage Mirroring can continue transmitting by using the schedule end command with the duration switch.
Transmission schedule examples This section shows examples of how the different schedule commands could be used together. NOTE: The numbers and times were randomly selected for these examples. Be sure to use values that work for your environment. Example 1—In this example, transmission is set to begin on January 12, 2007, at 10:30 p.m. and to end after 6 hours.
Controlling transmission manually To start, stop, pause, or resume the transmission of data from the source to the target, use the transmission command with the start, stop, pause, or resume switches. To start the transmission process, use the transmission start command.
Pausing Storage Mirroring Execution on the Target Storage Mirroring servers running version 4.2 or later can pause the execution of operations on the target, even if there are no active connections to that target. For targets that do have active connections, any operations already in progress are completed, while any new incoming operations are queued until execution on the target is resumed, at which time the queued operations are processed.
Resuming through the Management Console Use either of the following methods, to resume execution on the target: Right-click on the left pane of the Management Console, on a target server which you are logged in to, and select Resume Target. Right-click on a connection in the Target tab on the right pane of the Management Console and select Resume Target. If you have an established connection, verify in the Target Status field that the target is resumed.
11 X Failover Failover Failover is a component of Storage Mirroring that allows a target to stand in for a failed source machine. The failover target assumes the network identity of the failed source. When the target assumes the identity of the source, user and application requests destined for the source IP address(es) are routed to the target.
Failover Terminology Missed Packets—The missed packets is the configurable setting that specifies how many monitor replies can be missed before assuming the source machine has failed. Monitored IP Addresses—Monitored IP addresses are the IP addresses on the source selected to be monitored by a Storage Mirroring target. Monitor Interval—The monitor interval is the configurable setting that specifies how often the monitor request is sent to the source machine.
4. The failed source’s IP address and subnet mask are added to the target’s identity. Target Name: Backup IP Address: 125.7.82.67 and 125.7.82.43 Failed Source User and application requests are sent to the target by locating the IP address 5. Failover sends updates to routers and other machines with IP address mappings allowing clients to seamlessly attach to the target machine. All user and application requests destined for the source machine are routed to the target machine. 6.
How Failure Detection Works 1. The target sends a monitor request to each monitored IP address at a user-defined interval. A monitor reply is sent from the source back to the target. 2. When the user-defined number of missed packets is met, the address is considered failed.
Failover Hardware Configurations Failover can be configured to stand in for one or more IP addresses associated with different NICs on the source. Each IP address can be added to a specific target NIC making NIC configuration very flexible. Following are some sample configurations. NOTE: If a failover target is monitoring a source for failure and a new NIC is added to the target server, you will need to reinstall Storage Mirroring to properly setup the new NIC for failover placeholders.
Multiple NICs on the source and target With any source configuration, additional NICs on the target increases flexibility and control. Secondary target NICs can assume the traffic from a failed source NIC while normal target traffic can continue to use the primary target NIC. Multiple sources can be directed to specific NICs. For example, a single target containing three NICs monitors three source machines located on different subnets. Each source has one NIC attached to a different subnet.
Failover Options In order for failover to stand in for a failed machine, you must configure the monitoring and failover options. These options are the same regardless of the configuration method (Management Console, Failover Control Center, or Text Client) that you use. Source Machine—The machine that is monitored for failure. IP Addresses—The machine that is monitored for failure may have one or more IP addresses.
Managing Failover Through the Failover Control Center Through the Failover Control Center, you can configure and monitor the failover process. The failover settings determine what users experience during a failover. In addition, the Failover Control Center can be used to initiate the failback process and to offer additional options. Configuring monitoring and failover 1. The Failover Control Center can be started from within the Management Console or from the Windows desktop.
5. 6. Specify your source machine by any of the following methods: Type the name of the machine that you want to monitor in Machine Name(s) and click OK. You can enter multiple names if you want to monitor more than one machine by separating the names with a space. Click Custom, specify the IP address (with or without a port number) of the machine you want to monitor, click OK. If your Linux server is advertising iself via NETBIOS, click Browse to search for a machine.
12. Specify if you want to Failover IP Address(es) on the source to the target. NOTE: When multiple IP addresses are monitored, there is the potential for IP address conflicts during failover. Conflict may occur when the number of IP addresses that trigger failover is less than the number of IP addresses that are assumed by the target during failover. For example, suppose a source machine has three IP addresses and two of these are monitored.
Monitoring failover Now that replication and failover monitoring are configured and started, you will need to know if and when there is a problem. Since it can be essential to quickly know the status of your machines, Storage Mirroring offers various methods for monitoring the status of failover.
The following table identifies how the visual indicators change as the status of failover changes. Time to Fail Countdown Source is Online Source Fails and Failover is Initiated Failover is Complete Status Bar Colored Bullets Desktop Icon Tray The Time to Fail counter is counting down and resetting each time a heartbeat is received from the source machine. The status bar indicates that the target machine is monitoring the source machine. The bullets are green.
4. Select the failed source and click Failback. If you specified a pre-failback script in your failover configuration, that script will be executed at this time. 5. You will be prompted to determine if you want to continue monitoring the source. Bring the source online and select Continue or Stop to indicate if you want to continue monitoring the source. After you have selected whether or not to continue monitoring the source machine, the source post-failback script, if configured, will be started.
Communication ports The Storage Mirroring daemon and the Failover Control Center use two ports for various Storage Mirroring communications. Service Transmit Port—The Failover Control Center uses this port to send commands to Storage Mirroring servers. Heartbeat Listen Port—The Failover Control Center uses this port to listen for heartbeats transmitted from Storage Mirroring servers. To view or modify the port settings in the Failover Control Center, select Settings, Communications.
Testing failover The failover process, including pre-failover and post-failover script processing, can be tested at any time. To force unavailability, disconnect the network cable from a monitored machine, wait for the Time to Fail counter to decrease to zero and failover begins. To avoid the countdown delay, highlight the monitored machine name in the Failover Control Center window and select Failover. NOTE: Remove the source from the network before testing failover.
Managing Failover Through the Text Client Through the Failover Control Center, the failover process can be configured, monitored, and tested. In addition, the Failover Control Center can be used to initiate the failback process. Configuring monitoring and failover 1. If you are using Storage Mirroring replication, establish a source/target connection by following the steps in Establishing a new connection on page 6-12. 2. Specify a target machine by using the target command. 3. 4.
5. 6. Specify that you want to use the monitor that was just created by using the monitor use command. Command MONITOR USE Description Specifies the source machine designated as the monitor that will be used in subsequent monitor commands Syntax MONITOR USE Options monitor—Name of the source machine designated as the monitor Examples monitor use indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
7. To remove an IP address from an established monitor, use the monitor remove command. Command MONITOR REMOVE Description Removes an IP address that is currently being monitored Syntax MONITOR REMOVE [monitor] Options IP_address—The currently monitored IP address that should be removed monitor—Name of the source machine designated as the monitor monitor remove 205.31.2.57 indy monitor remove 205.31.2.68 Examples Notes 8.
Options MOVENAME—Moves the server name during failover NOMOVENAME—Does not move the server name during failover MOVEADDRESSES—Moves the IP address(es) during failover NOMOVEADDRESSES—Does not move the IP address(es) during failover MOVESHARES—This is a Windows only option NOMOVESHARES—This is a Windows only option ADD—Specifies the source machine’s identity is added to the target machine’s identity when failover occurs REPLACE—Specifies that the source machine’s identity repl
9. Specify any scripts by using the monitor script add command.
10. Remove any scripts by using the monitor script remove command.
Storage Mirroring version 4.
14. If you need to clear the monitor settings so that they can be reconfigured, use the monitor clear command. Command MONITOR CLEAR Description Clears all of the failover configuration and monitoring parameters for the specified monitor machine Syntax MONITOR CLEAR [monitor] Options monitor—Name of the source machine designated as the monitor Examples monitor clear indy Notes If you do not specify a monitor, the current source designated as the monitor will be used.
Initiating failback When failover occurs, a source machine has failed. The steps below must be completed in order to complete failback without IP address or name conflicts. 1. Verify the source machine is not connected to the network. If it is, disconnect it. 2. Resolve the source machine problem that caused the failure. WARNING: Do not connect the source machine to the network at this time. 3. 4. 5.
12 X Restoration Restoration The Storage Mirroring restoration process provides an easy method for copying replicated data from the target back to its original location on the source. The process only requires you to select the source, target, and the appropriate replication set. There is no need to select files or to remember where the data came from on the source since that information is maintained by Storage Mirroring.
How the Restoration Process Works 2 3 3 5 Replication Set Replication Set Backup 6 1 Source 4 Target File Conditionals 1. The network administrator resolves the source machine problems and in the process reinstalls Storage Mirroring, if necessary. 2. The network administrator initiates restoration through one of the Storage Mirroring clients. 3.
Restoration Options When restoring Storage Mirroring data, you must specify the source and target machines and the replication set from the source machine that contains the data that was lost and needs to be restored, as well as configure how the restoration process will occur. Original Source—If you are restoring to a Storage Mirroring server other than where a replication set was created, you must specify the original source machine.
Restoration Conditional Options Only if Backup Block Checksum is Overwrite Files All Server Newer Restoration Properties Restoration Option Source Taba Option Block Checksum Restoration Option Action Performed (3 ) If no restoration options are selected, only the files that exist on the target but not on the source will be transmitted to the source. (3 ) 3 All files on the target are restored to the source. The restoration sends the entire file.
Restoring Storage Mirroring Data Through the Management Console 1. From the Management Console, select Tools, Restoration Manager. 2. Select the Original Source machine. This is your source machine where the data originally resided. 3. Select the Restore From machine. This is the target machine where the backup data is stored. 4. Replication Set contains the replication set information stored on the target machine (the machine in Restore From).
7. Select the Use Backup Replication Set check box to use the backup of the replication set stored on the target machine for the restore. If this check box is not marked, you will be accessing the replication set from the source machine. 8. Select the Restore Replication Set check box to restore the target’s backup of the replication set database to the source machine during the restore process. 9. Select the restoration conditionals that you want to use.
Restoring Storage Mirroring Data Through the Text Client 1. Log on to your source machine using the login command. Command LOGIN Description Log on to a Storage Mirroring machine Syntax LOGIN [domain] Options machine—Name of the machine username—Name of the user password—Password associated with username. domain—If logging in using a domain account, this is the domain name. If logging in using a local account, this is the machine name.
4. Restore Storage Mirroring data from target to the source by using the restore from command.
Automating Restore You can use a post-failback script on the source to automate the restore process. Use the following file as a sample. SPOSTBACK.TXT # # # # # # # # # # # # SAMPLE SOURCE FAILBACK AND RESTORE SCRIPT THIS POST-FAILBACK SCRIPT EXECUTES ON THE SOURCE. THIS SCRIPT PERFORMS A TARGET-SOURCE RESTORE AND REESTABLISHES THE CONNECTION AND STARTS MIRRORING.
SPOSTBACK.TXT (continued) # Restore target data to source before # recreating original connection # Restore ID should be 1 or greater, so exit on failure $restID=RESTORE from original overwrite; if $restID < 1 then WRITE “restore failed from ”; WRITE $restID; quit; end SOURCE ; WAITONRESTORE $restID; # Add a hard wait of 20 seconds to clear queues.
13 X Monitoring Tools Monitoring Tools Storage Mirroring offers a variety of tools for monitoring Storage Mirroring activity. With these monitoring tools, you can obtain the status of Storage Mirroring machines, connection statistics, and alerts. Alerts are processing notifications, warnings, and/or errors. The Management Console main window displays source/target connection and statistical information in the right pane.
Management Console Statistics By highlighting a source on the left pane of the Management Console main window, the current connections and their statistics are displayed on the right. Scroll to the right to view the additional statistics. The following table lists each statistic available for the Management Console main window and what that statistic identifies. The statistics marked with an asterisk (*) are not displayed by default.
Statistic Replication Status Description Replicating—Data Ready—There is being replicated to the target machine. Stopped—Replication Pending—If auto-remirror is enabled and you have experienced a source or target failure and recovery, the status will change to pending while the connections are reestablished and will update when the remirror begins.
Customizing the statistics You can change the statistics that are displayed on the Management Console main window by following these steps: 1. Select File, Options and click the Statistics tab. The statistics will be listed with check boxes to the left of each item. 2. Mark the check box to the left of each statistic that you want to appear on the Management Console main window. 3. Clear the check box to the left of each statistic that you do not want to appear on the Management Console main window.
At-a-Glance Monitoring At-a-glance monitoring includes icons and colors that indicate the status of Storage Mirroring machines and connections. Each icon or color that indicates the status of Storage Mirroring activity is described in the following tables. The icons in the left pane indicate what modules are loaded on each machine. Left Pane Icons Icon Description The world icon is selected. The Storage Mirroring machines are displayed in the right pane of the Management Console.
Left Pane Right Pane Description Target Machine Source Tab The display is blank. Target Machine Target Tab The active connections, if any, to that target machine are displayed. Replication Set No Tabs The available target machines are displayed so that you can drag and drop a replication set onto a target to establish a connection. Volume or Directory No Tabs The directories and files contained in that volume or directory are displayed. a a.
The following table identifies the different icons and colors that you may see in the right pane of the Management Console when you have a machine with an established connection selected. These icons let you know, at-a-glance, the status of your Storage Mirroring connections. Connection Icons Icons and Colors Description A green checkmark appears in the right pane of the Management Console to the left of the connection data line for an established connection that is working properly.
Customizing when the background color and icons change Communications between the Management Console and the source are monitored by requests and responses. The Management Console sends a request to the source and expects a response back. If the Management Console exceeds the number of responses that can be missed, the Management Console changes icons and color to alert you to potential problems.
Management Console Message Window The Management Console message window displays Storage Mirroring processing alerts. These alerts include notifications, warnings, and errors. Use the instructions below to create and control the Management Console message window. NOTE: The standard appearance of the message window is a white background. If your message window has a gray background, the window is inactive.
2. To control the window after it is created, use either of the following methods to access the control methods listed in the table: Right-click on the message window and select the appropriate control. Select the appropriate toolbar control Select Monitor, the name of the message window, and the appropriate control. Message Window Control Description Close Closes the message window Clear Clears the message window Pause/ Resume Pauses and resumes the message window.
Text Client main window After a source/target connection is established, the Text Client main window displays basic connection and statistical information for the active source machine. NOTE: Use the source command to set a machine as the active source. The Command Line Client does not display connection and statistical information. Storage Mirroring version 4.
DTCL status command Use the status command to display connection and status information as described in the table below.
Linux System Log An event is a significant occurrence in the system or in an application that requires administrators to be notified. The operating system writes notifications for these events to the Linux system log. The location of the log file depends on the configuration of /etc/syslog.conf, but by default it is in the /var/log/messages. The following table identifies the events generated by Storage Mirroring.
Category DblTake ID Severity Message Required Response 16385 Info Reboot the server and contact Internal function ReferenceOrBuildStreamInfo returned technical support if this event occurs an unexpected result. The last Word again. in the Data Window is the NT status code. 16386 Info A very large write was logged. The last Contact technical support. Word in the Data Window is the number of bytes written. Please save this event log and contact technical support.
Category Failback Failover Monitoring NSIPHDriver ID Severity Message Required Response 5200 Info Failback completed for %1. No action required. 5201 Info IP address %1 was removed from target machine's %2 adapter. No action required. 5202 Error Unable to Failback properly because IP Contact technical support. address %1 was missing a corresponding SubNet Mask. 5100 Info Failover completed for %1. No action required.
Category NSIPHDriver ID Severity Message Required Response 9004 Error Could not allocate buffer to hold initial Reboot the server and contact IP address list for adapter technical support if this event occurs again. 9005 Error Could not allocate buffer to hold initial Reboot the server and contact subnet mask list for adapter technical support if this event occurs again.
Category Resources Service ID Severity Message Required Response 8200 Warning Failed to allocate buffer for querying Reboot the server and contact very long filenames, i.e., names over technical support if this event occurs 260 characters. Replication will again. continue for standard length filenames. The last Word in the Data Window is the NT status code. 8201 Warning Reached stop replicating page limit. Replication is stopped.
Category Service ID Severity Message Required Response 4017 Info Service has disconnected from %1 for No action required. Replication Set %2, ID: %3 4018 Warning %1, however, mirroring and replication Perform a restoration. have been disabled as a restore is required due to a previous failover. 4019 Info Service has started a mirror to %1 for No action required. Replication Set %2, ID: %3 4020 Info Service has paused a mirror for ID: %1 No action required.
Category Service ID Severity Message Required Response 4034 Error Error verifying the service name. The Reinstall the software, using the product functionality has been installation Repair option, to install a disabled. new copy of the RSResource.dll. Contact technical support if this error persists. 4035 Error Error verifying the product name. The Reinstall the software, using the product functionality has been installation Repair option, to install a disabled. new copy of the RSResource.dll.
Category Service ID Severity Message Required Response 4110 Warning Target can not write %1 due to target The disk on the target is full. The disk being full. Operation will be operation will be retried according to retried (%2 times or forever) the TGExecutionRetryLimit setting. 4111 Warning Target can not write %1 due to a sharing violation. Operation will be retried (%2 times or forever) 4112 Warning Target can not write %1 due to access An access denied error is prohibiting denied.
Category Service System ID Severity Message Required Response 5002 Info Placeholders were modified to %1. No action required. 10000 Error Connect failed to node %1 for resource %2. Adding node to reconnect list. Ensure that GeoCluster is running on all possible owners and that it can communicate on the network selected for mirroring and replication traffic. GeoCluster will try to reestablish a connection using the check unresponsive node interval specified for the resource.
Category System ID Severity Message Required Response 4100 Error Failed to open file. The Status and IoStatusBlock status are in the data window. 4100 Warning Failed to obtain a name for a Contact technical support. recognizer device object. The second to the last Word in the Data Window is a pointer to the device object. The last Word in the Data Window is the NT status code. 4101 Info An error occurred while trying to Contact technical support. identify the system volume.
DTStat Statistics logging is the process of taking snapshots of Storage Mirroring statistical data and writing it to a file for future use. Statistics are automatically gathered and written to disk by the Storage Mirroring daemon. The DTStat file can be configured from both the Management Console and text clients and any configuration changes are detected and applied immediately without restarting the Storage Mirroring daemon.
Modifying the log file settings through the Management Console 1. Right-click a machine in the left pane of the Management Console and select Properties. 2. Select the Logging tab. 3. At the top of the tab, specify the Folder where the log files for messages, alerts, verification, and statistics will be saved. 4. Under Statistics, specify the following information: 5. Filename—The name of the statistics log file. The default file name is statistic.sts.
Modifying the log file settings through the text clients 1. To determine the current location where the log file is stored, use the get command with the StatsFileName option. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Running DTStat You can run DTStat from the Storage Mirroring Text Client or from any command prompt. Running DTStat from the text clients To determine the status of DTStat or to stop or start it through the Text Client, use the statslog status, statslog start, or statslog stop commands. Starting DTStat Command STATSLOG START Description Starts the DTStats statistics logging utility.
Running DTStat from the command prompt From a command prompt, use the DTStat command from the location where Storage Mirroring is installed. Command DTSTAT Description Starts the DTStats statistics logging utility from a command prompt.
DTStat statistics The following statistics appear in the statistic.sts file. If you convert that file to an ASCII, comma-delimited file using the dtstat -s option, the heading labels may appear slightly different. Category Statistic Description Date/Time Stamp The date and time that the snapshot was taken. This is the date and time that each statistic was logged. By default, these are generated once a second, as long as there are statistics being generated.
Category Target a Source Connection Statistic Description Peer Address The IP address of the source machine Ops Received The total number of operations received by this machine as a target since the Storage Mirroring daemon was loaded MirrorOps Received The total number of mirror operations received by this machine as a target since the Storage Mirroring daemon was loaded. This number does not reset to zero for remirrors.
Category Connection Statistic conState Description The state of the active connection 0—Error. This indicates a connection that is not transmitting because something has gone wrong (for example, lost connection). 1—Active. This indicates that the connection is functioning normally and has no scheduling restrictions imposed on it at this time. (There may be restrictions, but it is currently in a state that allows it to transmit.) 2—Paused. This indicates a connection that has been paused. 3—Scheduled.
Category Connection Statistic Description conTask Cmds Submitted The number of task commands that have been submitted on the source conTask Cmds Queued The number of task commands that have been queued on the source conTasks Succeeded The number of task commands that have succeeded on the source conTasks Failed The number of task commands that have failed on the source conTasks Ignored The number of task commands that have been ignored on the source a.
LogViewer LogViewer is a utility that gathers Storage Mirroring alerts. These alerts, which are proccessing notifications, warnings, and error messages, are written to disk and can be displayed using the LogViewer. Sample LogViewer Output 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 01/15/2007 14:14:18.3900 14:14:18.4200 14:14:18.5350 14:14:18.6760 14:14:18.9870 14:24:15.2070 14:24:16.3090 14:24:40.9680 14:25:22.4070 14:25:22.
LogViewer log file Each log file consists of a base name, a series number, and an extension. Base Name—The base name is determined by the application or process that is running: Component Log File Base Name Storage Mirroring dtlog Management Console mc Failover Control Center fcc Text Client dttxt Command Line Client dtcl Series Number—The series number ranges from 1 to 999. For example, Storage Mirroring begins logging messages to dtlog1.
Modifying the log file settings through the Text Client 1. To determine the current location where the log file is stored, use the get command with the LogDir option. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Viewing the log files Use the LogViewer command from the directory where Storage Mirroring is installed to view a Storage Mirroring log file. Command LOGVIEWER Description The Storage Mirroring logging utility that records alerts (processing notifications, warnings, and errors) that occur during Storage Mirroring processing.
LogViewer Messages The following table describes the standard Storage Mirroring alerts that may be displayed in the LogViewer. The ID appears in column 7 of the LogViewer, and the message appears in column 8 of the LogViewer. In the following table, con_id refers to the unique connection ID assigned to each connection between a source replication set and a target. NOTE: ID Message Description 0 N/A There are several log messages with this ID#.
ID Message Description 79 Memory freed to bring Storage Mirroring memory usage below the limit Data in the source queue has been sent to the target machine, bringing the pagefile below its limit. 80 Trying to auto-retransmit to ip://xxx.xxx.xxx.xxx Storage Mirroring is attempting to automatically reconnect previously established source and target connections after a server reboot or auto-disconnect. This is also referred to as the auto-reconnect process.
ID Message Description 102 Target full! 801 Auto-disconnect has occurred on IP address Auto-disconnect has occurred for the specified connection. This address with connection con_id Disconnected is due to the source queue filling up because of a network or replication set name: repset_name. target failure or bottleneck. 10001 Activation key is not valid. An invalid activation code was identified when the Storage Mirroring daemon was started. 10002 Evaluation period has expired.
ID Message Description 54000 Kernel started The Storage Mirroring daemon was started. 54001 Failover module failed to load The Storage Mirroring failover module failed to load. Look at previous log messages to determine the reason. 54503 Failover module stopped The Storage Mirroring failover module stopped. 99001 Starting source module low memory processing The source’s queue is full, and the auto-disconnect process will disconnect the source and target connection.
14 X Advanced Settings Advanced Settings The Storage Mirroring program settings are the user-definable options that control Storage Mirroring application settings and Storage Mirroring processing settings. This includes options like the name of the verification log file and the size of the Storage Mirroring memory pool. Changing the Settings Through the Management Console All of the Storage Mirroring server settings are located in the Server Properties dialog box.
Storage Mirroring Version Information—The Storage Mirroring version number and build number are displayed. Activation Code—This is the Storage Mirroring license which is required on every Storage Mirroring machine. There are three licenses available: Evaluation—A license that has an end date built into the activation code. When the license expires, the software will no longer function. The same evaluation licenses can be used on multiple machines on a network.
Setup options The Setup tab consists of settings that are initialized when Storage Mirroring is started. Log Statistics Automatically—This check box indicates whether Storage Mirroring statistics logging, which logs to the statistic.sts file, will start when Storage Mirroring is started. For detailed information on the Storage Mirroring statistics logging, see DTStat on page 13-23. Enable Task Command Processing—This check box indicates whether task command can be processed on this server.
Network options The Network tab consists of settings that control network communications. Any changes made to this tab will not take effect until the Storage Mirroring daemon has been restarted on the specified machine. Interface Default Address—On a machine with multiple NICs, you can specify which address Storage Mirroring traffic will use. It can also be used on machines with multiple IP addresses on a single NIC.
Queue options The Queue tab consists of settings for Storage Mirroring queue usage. Folder—This is where the queue will be stored. For best results and reliability, you should select a dedicated, non-boot volume. Maximum system memory for queue—This is the amount of system memory that, when exceeded, will trigger queuing Maximum disk space for queue—This is the maximum amount of disk space in the specified Folder that can be used for to disk. Storage Mirroring queuing.
Source options The Source tab consists of settings specific to the source module of Storage Mirroring. Replication Packets to 1 Mirror Packet—This option allows you to specify the ratio of replication packets to mirror packets that are placed in the source queue. Specify a larger number if you have a busy network that has heavy replication. Also, if you anticipate increased network activity during a mirror, increase this number so that the replication queue does not get too large.
Target options The Target tab consists of settings specific to the target module of Storage Mirroring. Target Mirror Capacity High Percentage—This option specifies the maximum percentage of system memory that can contain mirror data before the target signals the source to pause the sending of mirror operations. The default setting is 20.
Database options The Database tab consists of settings that specify the name and location for the database files used by Storage Mirroring processes. Folder—Specify the directory where each of the log files on this tab are stored. The default is /var/lib/StorageWorks/StorageMirroring. Replication Set—This database file maintains which replication sets have been created on that machine along with their names, rules, and so on. The default file name is DblTake.db.
Logging options The Logging tab consists of settings for various log files. Folder—Specify the directory where each of the log files on this tab are stored. The default is /var/log/StorageWorks/StorageMirroring. Messages & Alerts Maximum Length—Specify the maximum length of the Storage Mirroring alert log file. The default size is 1048576 bytes and is limited by the available hard drive space. Maximum Files—Specify the maximum number of Storage Mirroring alert log files that are maintained.
Changing the Settings Through the Text Client Changing Storage Mirroring settings using the Text Client can be confusing because the settings for a Storage Mirroring source or target are stored in the same location as the settings for the Storage Mirroring Text Client. Therefore, if you are running a Storage Mirroring source or target on the same machine that you are running the Text Client, and you update a client setting, you are also updating that setting on the source and/or target.
Storage Mirroring Text Client program settings The following table contains a complete listing of each Storage Mirroring program setting. Program Setting ActivationCode Description 16-character Storage Mirroring activation code Values: Found on registration card, if not an evaluation copy Default: n/a AdapterFlags Specifies the adapter to use when establishing a connection Values: (1) Compression (2) Encryption (4) Network Data Representation Default: 4 Compression is no longer used.
Program Setting AutoRemirrorRetry Description Specifies how often, in seconds, the source should check for connections that have been reconnected but still need to be remirrored Values: any integer Default: 30 AutoRetransmit Determines whether or not a source that has lost its connection with a target will attempt to reconnect to the target Values: (0) Do not attempt to reconnect (1) Attempt to reconnect Default: 1 BackupDir Location on the target of the backup of the replication sets Values: any valid
Program Setting ClientLog Description Indicates whether commands entered in the Text Client are tracked Values: (0) Not tracked (1) Tracked Default: 0 If you change this value, the Text Client must be closed and restarted to implement the change. ClientLogName Name of the log file that tracks commands entered in the Text Client Values: any valid file name Default: Dttext.log If the name of the log file is changed, the Text Client must be closed and restarted to start logging to the new log file.
Program Setting DriverMode Description Specifies the type of I/O control Values: (0) No paging or throttling (1) Throttling (2) Paging (3) Mixed, both throttling and paging Default: 3 DropOpOnHandle Error Determines if an additional attempt is made to access a file by a Microsoft API call if the Storage Mirroring call fails.
Program Setting FailoverHostname Description Automatically removes the host SPN (Service Principle Name) from Active Directory on the source Values: (0) Disabled (1) Enabled Default: 0 If you are using Active Directory, this option should be enabled or you may experience problems with failover.
Program Setting HBTTL Description Number of seconds without receiving a heartbeat before a remote machine is considered unavailable Values: 0 - 65535 Default: 10 HeartbeatIgnoreIPs Indicates an IP address to be ignored by the Management Console. An ignored IP address will not be displayed in the Management Console servers tree. Values: an IP address in the format x.x.x.
Program Setting IPFailover Description Specifies whether or not to failover the IP addresses during failover Values: (0) Do not failover IP addresses (1) Failover IP addresses Default: 1 LanguagesAvailable Specifies the Storage Mirroring language support that has been installed. Do not modify this setting. If you need to add or remove language support, use the Storage Mirroring installation program.
Program Setting MaxConnections Description Number of network requests that can be processed simultaneously. Values: 0 - 65535 Default: 5 HP recommends that you not change this value. MaxDriverPagefile Size Specifies the amount of disk space, in MB, to use for Storage Mirroring driver paging Values: 64-4095 Default: 256 The Storage Mirroring driver pagefile is located in the directory specified by QJournalDir. MaxLogFileSize Maximum size, in bytes, of any .
Program Setting MirrorChunkSize Description Block size (in bytes) used in the mirroring process Values: 1 - 375000 Default: 32768 (32K) A higher block size value gives you better throughput, but only to a certain point, then it starts using more memory because of the way memory is allocated and deallocated. A lower block size value produces slower throughput, but uses memory efficiently. The optimal value is 32768. The MirrorChunkSize should not be larger than the TCPBufferSize.
Program Setting NetworkRetry Description Specifies the interval, in seconds, at which Storage Mirroring will attempt to reconnect to the target Values: any positive number Default: 10 NetworkStatus Interval This entry is no longer used. NetworkTimeout The maximum length of time, in seconds, to wait on a network connection. If data is not received over a network connection within the specified time limit, the connection is closed.
Program Setting PreFailoverWait Description Specifies whether or not to wait for the pre-failover script to complete before finishing a failover Values: (0) Do not wait (1) Wait Default: 0 PriorityClass The priority level at which the daemon runs. Values: 2 Default: 2 ProductCode Used by the Storage Mirroring installation program to maintain the installation settings for an upgrade QJournalDir The location where the queue is stored.
Program Setting Description Registered This entry is no longer used. RemapLink Specifies how Storage Mirroring handles a soft link Values: (0) If a soft link exists in a replication set and points to a file or directory inside the replication set, the path contained in the link will retain its original mapping.
Program Setting ScheduleFile Description Name of the database file that contains transmission scheduling information Values: any valid file name Default: Schedule.db If you change the name of the database file, the source daemon must be stopped and restarted to start logging to the new database file.
Program Setting Description StatsMaxObjects This entry is no longer used. StatsPort Port used by DTStat to gather Storage Mirroring statistics Values: 1025 - 65535 Default: 1106 If you change this value, the source daemon must be stopped and restarted to implement the change. StatsShmSize This entry is no longer used. StatsWriteInterval Interval, in minutes, in which statistics are written to the statistic.
Program Setting TGFileAlloc Description Indicates that Storage Mirroring allocates an entire file on the first write of a mirror operation Values: (0) Disabled (1) Enabled Default: 1 To help eliminate file fragmentation on the target server, Storage Mirroring should allocate the entire file first. With extremely large files, the file allocation may take a long time. Therefore, you may want to disable the file allocation. If you disable file allocation, you will have more fragmentation on the target disk.
Program Setting UNetPort Description Port connection for UDP communications Values: 1025 - 65535 Default: 1500 If you change this value, the source daemon must be stopped and restarted to implement the change.
Program Setting VersionInfo Description The version of Storage Mirroring that was installed Value: determined by the version installed Default: determined by the installation WarningPings This entry is no longer used.
15 X Security Security To ensure protection of your data, Storage Mirroring offers multi-level security using native operating system security features. Privileges are granted through membership in user groups defined on each machine running Storage Mirroring. To gain access to a particular Storage Mirroring source or target, the user must provide a valid operating system user name and password and the specified user name must be a member of one of the Storage Mirroring security groups.
Clearing Maintained Security Credentials To remove the credentials, follow these steps: 1. To access the credentials security option, click File, Options and select the Security tab. 2. To remove the security credentials, click Clear Cached Security Credentials. 3. Click OK.
A X Storage Mirroring Commands Storage Mirroring Commands The Double-Take Command Language (DTCL) is a scripting language that can be used in either the Text Client or Command Line Client to manage and monitor Storage Mirroring components. It can also be used in script files to execute series and combinations of commands to meet specific needs.
Connect Command CONNECT Description Establishes a connection between a replication set and a target machine Syntax CONNECT TO MAP EXACT | BASE | TO [,...
Connect TDU Command CONNECT TDU Description Establishes a connection between a replication set and the Throughput Diagnostics Utility to imitate a normal connection without transmitting any data across the network Syntax CONNECT TO TDU [connection flags] Options repset—Name of the replication set file_name—Name of the file to store the connection statistics generated by the TDU connection flags—The same options available in the standard connect command connect “Cus
DTStat Command DTSTAT Description Starts the DTStats statistics logging utility from a command prompt.
Environment Command ENVIRONMENT Description Displays a list of all Storage Mirroring machines available to the specified machine. Each machine is identified by machine name, IP addresses and whether or not the source and/or target modules are loaded. If no machine is specified, the information is provided for the machine currently specified as the source.
Failover Command FAILOVER Description Manually initiates the failover process for the specified monitor machine Syntax FAILOVER [ON ] Options monitor—Name of the source machine designated as the monitor target_machine—Name of the target machine Examples failover indy on jersey Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
GetEnvStr Command GETENVSTR Description Retrieves an operating system environment variable and stores the value in a variable. Syntax GETENVSTR $ Options env_variable—The name of the operating system environment variable that you want to store in the user defined variable variable_name—The name of the variable you want to create. This variable will store the operating system environment variable specified.
Load Source Command LOAD SOURCE Description Loads the Storage Mirroring source module Syntax LOAD SOURCE Options machine—Name of the machine Examples load source indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Logout Command LOGOUT Description Logs off of a Storage Mirroring machine Syntax LOGOUT Options machine—Name of the machine Examples logout indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. LogViewer Command LOGVIEWER Description The Storage Mirroring logging utility that records alerts (processing notifications, warnings, and errors) that occur during Storage Mirroring processing.
Mirror Pause Command MIRROR PAUSE Description Pauses a mirror that is in progress Syntax MIRROR PAUSE Options con_id—Connection ID assigned to the source/target connection *—Specifies all connection IDs. mirror pause 1 mirror pause * Examples Mirror Resume Command MIRROR RESUME Description Resumes a paused mirror Syntax MIRROR RESUME Options con_id—Connection ID assigned to the source/target connection *—Specifies all connection IDs.
Mirror Start Command MIRROR START Description Initiates the mirror process Syntax MIRROR START [CLEAN | DIFFERENT [,NEWER] ,CHECKSUM] [ORPHANS |NOORPHANS] [CALCULATE] Options con_id—Connection ID assigned to the source/target connection CLEAN—Deletes all files in the specified target path prior to mirroring DIFFERENT—Mirrors only those files that are different based on the file date, time, and/or size NEWER—Mirrors only those files that are newer on the source than on the targ
Monitor Clear Command MONITOR CLEAR Description Clears all of the failover configuration and monitoring parameters for the specified monitor machine Syntax MONITOR CLEAR [monitor] Options monitor—Name of the source machine designated as the monitor Examples monitor clear indy Notes If you do not specify a monitor, the current source designated as the monitor will be used. If you have not identified a monitor, you will receive an error message stating that a monitor has not been selected.
Monitor Display Command MONITOR DISPLAY Description Displays the monitoring and failover configuration settings for the specified monitor machine Syntax MONITOR DISPLAY Options monitor—Name of the source machine designated as the monitor Examples monitor display indy Notes If you do not specify a monitor, the current source designated as the monitor will be used. If you have not identified a monitor, you will receive an error message stating that a monitor has not been selected.
Monitor Move Command MONITOR MOVE Description Designates the IP address that will be failed over to the specified target NIC.
Monitor Option Command MONITOR OPTION Description Configures the settings to determine how failover will be performed Syntax MONITOR OPTION [MOVENAME | NOMOVENAME] [MOVEADDRESSES | NOMOVEADDRESSES] [MOVESHARES | NOMOVESHARES] [ADD | REPLACE] [, USESHAREFILE | NOUSESHAREFILE][, FAILONE | FAILALL] [, TRIGGERONE | TRIGGERALL] [, FODELAY | NOFODELAY] [, FBDELAY | NOFBDELAY] [, INTERVENTION | NOINTERVENTION] [monitor] Options MOVENAME—Moves the server name during failover NOMOVENAME—Does not move t
Monitor Remove Command MONITOR REMOVE Description Removes an IP address that is currently being monitored Syntax MONITOR REMOVE [monitor] Options IP_address—The currently monitored IP address that should be removed monitor—Name of the source machine designated as the monitor monitor remove 205.31.2.57 indy monitor remove 205.31.2.68 Examples Notes If you do not specify a monitor, the current source designated as the monitor will be used.
Monitor Script Remove Command MONITOR SCRIPT REMOVE Description Specifies the scripts that should not be run during the failover and failback processes Syntax MONITOR SCRIPT REMOVE [monitor] Options type—Any of the following script types: PREFAILOVER—Specifies that the file is a pre-failover script to be run on the target before failover occurs POSTFAILOVER—Specifies that the file is a post-failover script to be run on the target after failover occurs PREFAILBACK—Specifies that t
Monitor Stop Command MONITOR STOP Description Stops monitoring the source machine for a failure Syntax MONITOR STOP [ON ] Options monitor—Name of the source machine designated as the monitor target_machine—Name of the target machine that will no longer be monitoring the source machine Examples monitor stop indy on jersey Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Orphans Start Command ORPHANS START Description Manual operation to remove any orphan files on the target Syntax ORPHANS START con_id Options con_id—Connection ID assigned to the source/target connection Examples orphans start 1 Orphans Stop Command ORPHANS STOP Description Stops the process to remove orphan files on the target Syntax ORPHANS STOP con_id Options con_id—Connection ID assigned to the source/target connection Examples orphans stop 1 Pause Target Command PAUSETARGET Descri
Ping Command PING Description Checks a specified machine to see if Storage Mirroring is running Syntax PING Options machine—Name of the machine Examples ping indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Quit Command QUIT Description Quits the Text Client and the Command Line Interactive client Syntax QUIT Queue Task Command QUEUETASK Description Queues tasks inline with replication data.
Options job_name—Any name that you have assigned to the job. This will be the identifier you will see in target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP the log files. address. Depending on the network route Storage Mirroring uses to access the target, you may need to specify the fully qualified domain name. The target is required even if you are only queuing a task to be executed on the source.
Replication Start Command REPLICATION START Description Initiates the replication process Syntax REPLICATION START Options conid—Connection ID assigned to the source/target connection *—Specifies all connection IDs replication start 1 replication start * Examples Replication Stop Command REPLICATION STOP Description Stops the replication process Syntax REPLICATION STOP Options conid—Connection ID assigned to the source/target connection *—Specifie
Repset Create Command REPSET CREATE Description Creates a replication set Syntax REPSET CREATE Options name—Name of the replication set Examples Notes repset create “Customer Data” repset create marketing Replication set names that contain non-alphanumeric characters must be enclosed in quotation marks. If the name of the replication set is the same as a word used in a DTCL command (for example, repset create repset), you will receive an error.
Repset List Command REPSET LIST Description Lists all replication set names for the currently selected source Syntax REPSET LIST Repset Resync Command REPSET RESYNC Description Retrieves the last saved replication set settings from the source. Syntax REPSET RESYNC Repset Rule Add Command REPSET RULE ADD Description Adds a rule to a replication set. A rule is the specification of a path including volume, directories, wild cards, and/or file names.
Repset Rule Remove Command REPSET RULE REMOVE Description Removes a rule from a replication set Syntax REPSET RULE REMOVE [FROM ] Options path—Volume, directory, wild card, and/or file name repset—Name of the replication set Examples repset rule remove /var/spool/customerDB from “Customer Data” Notes If you do not specify a replication set name, the current replication set will be used.
Restore Command RESTORE Description Initiates the restoration process Syntax RESTORE FROM [ORIGINAL ] [, OVERWRITE | NOOVERWRITE][, OVERWRITENEWER | NOOVERWRITENEWER] [, USETARGETDB | NOUSETARGETDB][, RESTOREDBTOO | NORESTOREDBTOO] [, CHECKSUM][, ORPHANS | NOORPHANS] Options repset—Name of the replication set target_machine—Name of the target machine original_source_machine—Specifies that the replication set was not originated on the curr
Resume Target Command RESUMETARGET Description Allows you to resume the execution of Storage Mirroring operations on the target Syntax RESUMETARGET Options target_machine—The name of the target machine where you want to resume execution of the Storage Mirroring operations Examples resumetarget jersey Notes You must be logged on to the target machine for this command to work.
Schedule Enable Command SCHEDULE ENABLE Description Enables the transmission schedule Syntax SCHEDULE ENABLE Options target_machine—Name of the target machine Examples schedule jersey enable Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Schedule Start Command SCHEDULE START Description Sets criteria to start the transmission of data from the source to the target Syntax SCHEDULE START [STARTTIME = ] [MEMLIMIT = ][QUEUESIZE = ] [EVERY ] Options target_machine—Name of the target machine mm/dd/yy—Date in month/day/year format indicating when the transmission will begin hh:mm—Time in hour:minute format using the 24 hour clock indicating when the transmissi
Set Command SET Description The Text Client/DTCL sends a request to Storage Mirroring to modify the value of a Storage Mirroring program setting. The setting is immediately applied and is then forwarded to the registry where it is also applied. Syntax SET
Shutdown Command SHUTDOWN Description Stops the Storage Mirroring daemon Syntax SHUTDOWN Options machine—Name of the machine Examples shutdown indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Statslog Status Command STATSLOG STATUS Description Identifies whether or not the DTStats statistics logging utility is currently running Syntax STATSLOG STATUS Options machine—Name of the machine Examples statslog status indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Statslog Stop Commatnd STATSLOG STOP Description Stops the DTStats statistics logging utility.
Target Command TARGET Description Identifies a machine as the active target machine Syntax TARGET Options target_machine—Name of the machine Examples target jersey Notes You must be logged into a machine using the login command before using the target command. Machine names that contain non-alphanumeric characters must be enclosed in quotation marks. Testcon Command TESTCONNECTIONS Description Sends a test command to determine if Storage Mirroring is running.
Transmission Pause Command TRANSMISSION PAUSE Description Pauses the transmission pause Syntax TRANSMISSION PAUSE Options target_machine—Name of the target machine Examples transmission pause jersey Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Unload Source Command UNLOAD SOURCE Description Unloads the Storage Mirroring source module Syntax UNLOAD SOURCE Options machine—Name of the machine Examples unload source indy Notes Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.
Verify Command VERIFY Description Verifies the integrity of the data between the source and target machines.
Wait on Mirror Command WAITONMIRROR Description This command is used in scripts to force the script to stop executing until the connection has finished mirroring or verifying. Syntax WAITONMIRROR Options con_id—Connection ID assigned to the source/target connection Examples waitonmirror 1 Wait on Restore Command WAITONRESTORE Description This command is used in scripts to force the script to stop executing until the connection has finished restoring.
Write Command WRITE Description Displays the value of a DTCL variable Syntax WRITE $ Options variable_name—The name of the variable that you have established and want to display its value Examples write $thetarget write $dbrepset A - 38
DTCL Scripting To simplify using Storage Mirroring and DTCL, you can create script files to execute series and combinations of commands to meet specific needs. NOTE: When creating DTCL scripts, each commented line must start and end with the pound (or number) sign (#). Each DTCL command and assignment must end with a semi-colon. However, no semicolon is necessary after the END keyword for the IF conditional and the loop statements.
WHILE Loop—The WHILE loop evaluates a relational expression and, if it is true, then the statement block is executed. When the statement block has completed execution, the expression will be reevaluated again and, if it is true, the statement block is executed again. This continues until the expression is false.
Error Code Description -122 The replication set you are attempting to create already exists. -123 The replication set you are attempting to delete does not exist. -124 The replication set you are attempting to manipulate does not exist. -125 The connection for which you are attempting to start or resume replication is already replicating. -126 The connection for which you are attempting to stop or pause replication is not replicating.
Error Code Description -205 The monitor set you are attempting to enable is already in use. -206 The monitor you are attempting to use with monitor set does not exist. -209 The machine you are attempting to failback is not failed over. -210 The machine you are attempting to failover is already failed over. -211 The machine you are attempting to failover is not currently being monitored. -213 IP address placeholders on the target are unavailable. -214 The specified target NIC was not found.
DTCL Scripting Examples This section shows examples of different script files. Basic getting started script The following script will start a Storage Mirroring connection by creating a repset called Customer Data and connecting it to the machine Jersey.
Basic flow control script The following script uses the IF conditional, FOR loop, and WHILE loop commands. In the following examples the FOR loop will start a mirror for all connections between 1 and 10. The IF conditional will return the error command “mirror failed to start” if a value of 0 is not obtained. The WHILE loop will wait for a mirror to end and disconnect as long as the returned value is less than 10.
B X Glossary Glossary Alerts—Notifications, warnings and errors that describe Storage Mirroring processes. Auto-disconnect—When the Storage Mirroring queue has reached its maximum, the auto-disconnect process empties the source queue and the source/target connection is broken. Auto-reconnect—The process that automatically reestablishes any source/target connections that were active before a Storage Mirroring failure on the source machine.
Index connect 6-12, 7-11, 8-5, A-2 connect tdu 6-14, A-3 active/active 1-8 connection active/standby 1-7 auto-disconnect 6-5 administrator access 15-1 auto-reconnect Management Console 2-5 Management Console 6-11 text clients 3-3 text clients 6-16 advanced settings disconnecting Management Console Management Console 6-7 database 14-8 text clients 6-14 general 14-1 display logging 14-9 Management Console 6-9 network 14-4 how it works 6-3 queuing 14-5 ID 6-3, 6-15 source 14-6 Management Console startup 14-3 a
H heartbeats 14-4 help A-7 Management Console 2-9 high availability 1-2 HP OpenView Storage Mirroring overview 1-1 I icons at-a-glance monitoring 13-5 connection display 6-9 connection statistics 6-9 Management Console 2-2, 13-5 ignore delete operations 14-6 include 5-1, 5-6, 5-8, 5-10, 5-15 insert server 2-8 interactive entry 3-2 L limit bandwidth 10-10, A-7 listing replication set 5-13, 5-16 load source A-8 load target A-8 log DTStat 14-9 LogViewer 13-33 verification Management Console 9-7, 14-9 overvie
replication capabilities 5-1 Management Console manually starting 8-3 manually stopping 8-3 monitoring 8-3 on connection 8-2 monitoring Management Console 8-3 on connection Management Console 8-2 text clients 8-5 options 8-1 N overview 1-4, 8-1 permissions niclist 11-16, A-18 Management Console 14-6 no access 15-1 starting Management Console 2-5 Management Console 8-3 text clients 3-3 text clients 8-7 stopping O Management Console 8-3 text clients 8-7 one-to-many configuration 1-10 text clients one-to-one m
setlocal A-30 shutdown A-31 single machine configuration 1-12 source 6-12, 7-11, 8-5, 9-9, 12-7, A-31 source/target functionality current session 3-5 statistics connection Management Console 6-8 statslog start A-31 statslog status 13-26, A-32 statslog stop A-32 status A-32 Storage Mirroring features disaster recovery 1-2 resource utilization 1-2 StorageWorks NAS Data Copy features backup 1-2 high availability 1-2 Storageworks NAS Data Copy features other 1-2 T target 11-16, A-33 testcon A-33 Text Client di
