Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide EK-HSG84-DT.
Notice © 2000 Compaq Computer Corporation. COMPAQ, the Compaq logo, and StorageWorks Registered in U.S. Patent and Trademark Office. SANworks, and the SANworks logo are trademarks or service marks of Compaq Technologies group, L.P. Microsoft, MS-DOS, Windows, and Windows NT are registered trademarks of Microsoft Corporation in the United States. All other product names mentioned herein may be trademarks and/or registered trademarks of their respective companies.
Contents iii Contents About This Guide Getting Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Compaq Website . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Compaq Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Precautions. . . . . . . . . . . . . .
iv Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Fully-Redundant Power—Optional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–7 Host Bus Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–7 Final Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–8 Software Components . . . . . . . . . . .
Contents v Chapter 3 Getting Started Site, Host, and Solution Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Host Bus Adapter Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Up the Fibre Channel Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Up the Fiber Optic Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vi Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Long Wave GBICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–31 Other Transport Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–31 Create Remote Copy Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–32 Before You Start . . . . . . . . .
Contents Initiator Site Clean Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unplanned Failover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Failover From the Target Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Full Failback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
viii Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Remote Copy Set Member Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–3 Remote Copy Set Worldwide LUN ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–4 Write History Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–4 Failure Notification . . . . . . . . . . .
Figures ix Figures Figure 1–1. ESA12000 Storage building block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–4 Figure 1–2. Additional components for Data Replication Manager. . . . . . . . . . . . . . . . . . . . . . 1–5 Figure 1–3. Fibre channel gigabit switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–6 Figure 1–4. Fibre channel-based DT storage subsystem (with fully-redundant power) . . . . . . 1–8 Figure 2–1.
x Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Tables Table 1–1 Table 1–2 Table 2–1 Table 4–1 Table 5–1 Table 5–2 Table 6–1 Table 6–2 Hardware Requirements Checklist and Part Numbers . . . . . . . . . . . . . . . . . . . . . . . 1–10 Software Requirements Checklist and Part Numbers . . . . . . . . . . . . . . . . . . . . . . . . 1–11 Data Replication Manager Switch Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–11 Restrictions . . . . .
About This Guide This guide describes the functionality of Data Replication Manager running on the HSG80 Array Controller. See the documentation that accompanied the subsystem for detailed information about subsystem enclosures and their components.
xii Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Precautions Follow the precautions listed in the sections “Electrostatic Discharge Precautions” and “Component Precautions” when carrying out the procedures in this guide. Electrostatic Discharge Precautions Static electricity collects on all nonconducting material, such as paper, cloth, and plastic.
About This Guide xiii Conventions This book uses the special notices and typographical conventions described in the following sections to help you find what you are looking for. Special Notices This book does not contain detailed descriptions of standard safety procedures; however, it does contain warnings for procedures that could cause personal injury, and cautions for procedures that could damage the controller or its related components.
xiv Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Text Conventions Convention ALLCAPS Meaning Command syntax that must be entered exactly as shown, for example: SET FAILOVER COPY=OTHER ALLCAPS Command syntax that is discussed within text, for example: “Use the SHOW SPARESET command to show the contents of the spareset.” MONOSPACED SCREEN DISPLAYS ARE IN UPPER-CASED MONOSPACED FONT.
About This Guide Related Publications The following table lists some of the documents that you will need to refer to when connecting, configuring, and operating your DRM solution. Document Title Part Number HSG80 Array Controller ACS V8.5 Configuration Guide 165144-001 / EK-HSG85-CG HSG80 Array Controller ACS V8.5 CLI Reference Guide 165145-001 / EK-HSG85-RG HSG80 Array Controller ACS V8.4/8.
xvi Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Data Replication Manager Solution Kits for Windows NT/Intel and OpenVMS Windows NT Solution Kit Part Number: QB-6BTAE OpenVMS Solution Kit Part Number: QB-6BTAC The following components should be included in your Data Replication Manager Solution Kit: ■ Compaq StorageWorks Data Replication Manager HSG80 Array Controller ACS Version 8.5P Operations Guide ■ Compaq StorageWorks HSG80 Array Controller ACS Version 8.
About This Guide Revision History The following revision history lists all revisions for this publication and the effective dates. Revision Level Date Revision C December 1999 EK-HSG84-DT.C01/128519-003 Revision B October 1999 EK-HSG84-DT.B01/128519-002 Revision A EK-HSG84-DT.
Chapter 1 Introduction to Data Replication Manager This chapter introduces Data Replication Manager and describes the required hardware and software components.
1–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide The DRM sites are connected over some distance via fiber optic cable or ATM. Data Replication Manager uses Fibre Channel gigabit switches to send the data between the sites. Other hardware may be inserted between the fibre channel switches if longer distances exist between sites.
Introduction to Data Replication Manager 1–3 NOTE: While this documentation addresses ESA12000 storage cabinets as the primary unit for Data Replication Manager configurations, Compaq’s DT solution will function in any equivalent cabinet that houses a BA370 enclosure. Connections between the controllers and hosts are made at each site with two Fibre Channel gigabit switches and two host bus adapters.
1–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Figure 1–1 shows these parts inside the ESA12000 cabinet with a 24 disk drive capacity. Subsequent sections outline additional hardware requirements needed to complete the Data Replication Manager solution. CXO6843A Figure 1–1.
Introduction to Data Replication Manager 1–5 Figure 1–2 highlights the specific components that must be added to the ESA 12000 building block to support a Data Replication Manager solution. 1 2 3 Top Fibre Channel Gigabit Switch, 8- or 16-port Bottom Fibre Channel Gigabit Switch, 8- or 16port Redundant Power Distribution Unit (optional) 1 2 3 CXO6844A Figure 1–2.
1–6 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Fibre Channel Gigabit Switch The Fibre Channel gigabit switch, shown in Figure 1–3, is used to connect the controllers to the hosts and to link the initiator and target sites together. The ports hold short- or long-wave Gigabit Interface Converters, which are described in the next section.
Introduction to Data Replication Manager 1–7 Fully-Redundant Power—Optional Fully-redundant power is an optional feature designed to offer a more secure source of power in the event that one or more units should fail. If less than five power components are operational, then the entire cabinet will shut down. This requires three additional power supplies and one additional AC power controller that plugs into one additional PDU. These additional components must be supplied for each BA370 enclosure.
1–8 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Final Assembly Your final DT setup should reflect Figure 1–4. CXO6842A Figure 1–4. Fibre channel-based DT storage subsystem (with fully-redundant power) NOTE: If you prefer to join cabinets for more storage capacity, follow the instructions in the RA8000 and ESA12000 Storage Subsystems User’s Guide, and be sure to establish the same setup at both the initiator and target sites.
Introduction to Data Replication Manager 1–9 Software Components This section describes the software components necessary to configure and manage a DT storage subsystem. For installation instructions, see the Configuration chapter. The following list shows the software required to enable Data Replication Manager: ■ Array Controller Software (ACS) Version 8.5P ■ Secure Path Version 2.2 (Required for Windows NT) ■ Storage Works Command Console (SWCC) Version 2.
1–10 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide The agent is a companion program to the client. This host-resident program is an interface between the client and the host’s storage subsystem that allows the two to communicate over a network. For a full description of SWCC and how it operates, refer to the StorageWorks Command Console Getting Started Guide.
Introduction to Data Replication Manager ATM Gateway Additional Hardware: ATM Gateway 166296-B21 2 per site ATM Gateway Service Kit 166297-B21 1 per site Table 1–2 Software Requirements Checklist and Part Numbers Required Software Part Number ACS V8.5P 128698–B21 / QB–6CAAA–SA Secure Path 2.2.2 380594–001 / QB–6695A–AA SWCC Version 2.
Chapter 2 Data Replication Manager Concepts This chapter explains Data Replication Manager concepts for configuring a Data Replication Manager solution. These include: Remote Copy Sets and Association Sets.
2–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Remote Copy Data Replication Manager uses the peer to peer remote copy function of the HSG80 controller to achieve data replication. HSG80 controller pairs at the initiator site are connected to their partner HSG80 controller pairs at the target site. Remote copy sets are created from units at the initiator and target sites. These remote copy sets are mirrors of each other.
Data Replication Manager Concepts 2–3 Operation Modes There are two possible remote copy operation modes: Synchronous or Asynchronous. Figure 2–1 shows the timeline differences between the two. Synchronous Operation Mode In synchronous operation mode, data is simultaneously written to the cache of the initiator subsystem and the cache of the target subsystems. The I/O completion status is not sent to the host until all members of the remote copy set are updated.
2–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Operation Mode Considerations ■ Synchronous replication is appropriate when exact consistency is critical to the business application. The application or application recovery depends upon data being written to both local and remote sites when completion is restored. ■ Synchronous operation may deliver best response time for heavy host write operations.
Data Replication Manager Concepts 2–5 Outstanding Write Operations Users should be aware that there is a controller-wide limit of 240 outstanding write operations even if the total is greater than 240. For example, you might have 12 synchronous remote copy sets each with a value of 100. The maximum outstanding writes are 240 and not 1200. When 240 outstanding writes are reached, then any new writes to the controller are queued.
2–6 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Error Mode SET RemoteCopySetName ERROR_MODE=FAILSAFE or NORMAL. The FAILSAFE ERROR MODE causes a remote copy set to become failsafe locked if the target becomes inaccessible or the initiator unit fails. When failsafe locked, the remote copy set is inaccessible. If a dual link failure occurs, the target is not removed, but is marked invalid. When the target is accessible again, a full copy operation is started.
Data Replication Manager Concepts 2–7 Association set 1 RCS1 RCS2 Unit LOCAL Unit Unit Unit REMOTE CXO7069A Figure 2–2. Association sets reside on the initiator controller pair All members of an association set must be on the same controller to enforce cache coherency. When members are added to an association set, they are moved to reside on the same controller and will failover together. Association set members can be either synchronous or asynchronous.
2–8 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide When NOFAIL_ALL is specified, the members of the association set react independently to failsafe locked conditions. One member of the association set becoming failsafe locked has no effect on the other members of the association set. NOFAIL_ALL is the default setting.
Data Replication Manager Concepts 2–9 Log Unit Restrictions ■ Up to 12 log units can be assigned (12 possible remote copy sets). ■ There can be only one log unit assigned to an association set. ■ Log units must be either a mirrorset or striped mirrorset. ■ Access must be disabled. ■ Write-back caching must be disabled. ■ Other unit settings must be the default settings. ■ Log unit must reside at the current initiator site. ■ Upon site failover the log unit and association set must be reconfigured.
2–10 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide ORDER_ALL When ORDER_ALL is enabled, the order of all asynchronous write operations across all members of the association set is preserved. No log unit is required. With the ORDER_ALL switch enabled and write history logging enabled, if one member of the association set starts write history logging, all members of the association set start write history logging.
Data Replication Manager Concepts 2–11 NOTE: If both links are severed, and the initiator configuration is functional, the system administrator must determine which site to use. Failback The failback method, full copy or fast-failback, will be determined by the enabling of Logging or Failsafe switches, the selected operation mode, and whether the failover is planned or unplanned as detailed in Table 2-1. The table also shows the availability of Association Set switches, ORDER_ALL and FAIL_ALL.
2–12 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Table 2–1 Data Replication Manager Switch Settings (Continued) Logging Enabled Logging Error Mode Failsafe Operation Mode Association Sets Failover Failback Failsafe is recommended for operations that can tolerate application halt during temporary target inaccessibility. Logging and Failsafe both Disabled: Not Recommended. Not Disaster Tolerant Logging and Failsafe both Enabled: Not Permitted.
Chapter 3 Getting Started This chapter explains how to get your Data Replication Manager solution ready for setup. NOTE: It a good idea to keep a copy of this manual at both the initiator and target sites, so as to ensure a successful and identical setup at both sites. Two copies will also eliminate confusion if more than one person is configuring Data Replication Manager.
3–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Host Bus Adapter Requirements To run your Data Replication Manager solution, you must have two host bus adapters installed into your host system. Refer to the KGPSA PCI-to-Fibre Channel Host Adapter guide that came with your adapter for detailed information on this hardware. At this time, it is important to locate and record the worldwide names of each host bus adapter.
Getting Started 3–3 4. Telnet into the switch. Username = admin and password = password (default setting). Make the following adjustments to the switch: ❏ Type switchName to configure the switch name. Be sure to designate a name that will enable you to easily identify the switch that you are trying to access. ❏ Type switchShow to reveal the status of the switch and some of its ports. ❏ Type version to display the firmware levels. You must be running version 1.6B or higher. 5.
3–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Getting Started 3–5 CAUTION: If the Fibre Channel optical cable is not properly connected to the controller, failure may result. Because of the cable’s frail nature, it must also be regularly maintained, or its performance and life span will be affected. Before proceeding, it is important to administer the precautionary measures detailed in the HSG80 Array Controller ACS Version 8.5 Maintenance and Service Guide.
Chapter 4 Configuring a Data Replication Manager Solution This chapter provides procedures for configuring your Data Replication Manager solution. Since a Data Replication Manager system spans multiple sites, you must configure the Data Replication Manager system at each site. The procedures take you through the configuration process. You will first set up the target site, then the initiator site. Setup for each site is very similar.
4–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Configuring a Data Replication Manager Solution 4–3 Figure 4–1 depicts a basic DRM configuration and will be referenced throughout this chapter. BuildngA BuildngB Host A Host B BuildngA BuildngB CXO7172A Figure 4–1. Data Replication Manager basic configuration Restrictions It is important to understand the operating restrictions before configuring your Data Replication Manager solution.
4–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Table 4–1 Restrictions (Continued) Restriction Maximum of 2 members allowed per Remote Copy Set (1 on initiator; 1 on target) Target unit cannot reside on the same controller pair as its initiator unit. Controller replication conducted through port 2 on each controller. Maximum 64 connections It is not possible to run DILX on units used by Remote Copy Sets.
Configuring a Data Replication Manager Solution 4–5 Configuring Overview Both the initiator and target sites need some type of CLI interface to the controller. You can connect the serial maintenance port of both the initiator and target site controllers to a terminal from which you issue CLI commands. You can also start a terminal emulator session on Windows NT. Use the HyperTerminal emulator. Settings are: 9600 baud, 8 bits, No parity, 1 stop bit, XON/XOFF.
4–6 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide ❏ LUNs. ■ Connect Fiber Optic Cables Between the Controllers and Switches. ■ Connect the Initiator Site to the External Fiber Link. ■ Create Controller Connections. ■ Enable Controller Connections on Target and Initiator Units. ■ Create Remote Copy Sets. ❏ Create Log Unit and Association Sets (optional). ■ Set Failsafe at the Initiator Site (optional). ■ Configure the Host. ❏ Install the Host Bus Adapters and Drivers.
Configuring a Data Replication Manager Solution 4–7 The first step to getting your DT system up and running involves setting up and configuring the controllers. These tasks are outlined below: 1. Ensure that all BA370 enclosures, Fibre Channel switches, Power Distribution Units (PDUs), and the main power supply are off. 2. Plug all cabinet PDU power cords into the main power receptacles. 3. Be sure that you have a serial connection to each of the controllers. 4. Apply power to the main power source. 5.
4–8 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide PORT_2_TOPOLOGY NOREMOTE_COPY = OFFLINE (offline) Cache: 512 megabyte write cache, version 0012 Cache is GOOD No unflushed data in cache CACHE_FLUSH_TIMER = DEFAULT (10 seconds) Mirrored Cache: Not enabled Battery: FULLY CHARGED Expires: NOCACHE_UPS Controllers misconfigured. Type SHOW THIS_CONTROLLER 11. Verify that the subsystem worldwide name, also called the NODE_ID, is set.
Configuring a Data Replication Manager Solution 4–9 NOTE: Once you have restarted the controller, you will see a series of %LFL, %CER, and %EVL prompts. These indicate a Last Failure Log, a CLI Event Report, and an Event Log, respectively. For a complete explanation of these event reports, refer to the HSG80 Array Controller ACS Version 8.5 Maintenance and Service Guide. 14. Issue a SHOW THIS command to verify that the worldwide name has been set.
4–10 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide NOTE: These settings will be automatically applied to controller B. Therefore, it is not necessary to repeat these steps again on controller B. 17. Verify that the settings have been accepted on controller B by using the following CLI command: SHOW OTHER_CONTROLLER FULL 18. Change your controller prompts to help you easily identify which controller you are working on.
Configuring a Data Replication Manager Solution 4–11 22. For OpenVMS: Set the SCSI version, alloclass, and identifier with the following commands: SET THIS SCSI_VERSION = SCSI-3 SET ALLOCLASS = 1 SET THIS IDENTIFIER = 99 Setting this switch causes the host to load the SYS$GDRIVER, which provides the GG devices. The value range is 1 - 99. 23.
4–12 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 25. Set the fabric topology for each port on both controllers using the following CLI commands: NOTE: You will be prompted to restart the controllers after each command, but you do not need to restart the controllers until all topologies have been set.
Configuring a Data Replication Manager Solution 4–13 After you have entered this CLI command, you will see a series of %LFL and %EVL displays, and the controllers will automatically restart. 29. Use the following CLI command to verify that these settings are in place: SHOW THIS_CONTROLLER . . .
4–14 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Configuring a Data Replication Manager Solution 4–15 1. Connect a multi-mode, 50-micron fiber optic cable from port 1 of the top controller to port 2 of the top Fibre Channel switch. 2. Connect a second multi-mode, 50-micron fiber optic cable from port 2 of the top controller to port 4 of the top Fibre Channel switch. 3. Connect a third multi-mode, 50-micron fiber optic cable from port 1 of the bottom controller to port 2 of the bottom Fibre Channel switch. 4.
4–16 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Long Wave GBICs 1. Connect a single-mode, 9-micron fiber optic cable from port 6 of the top switch to one connection point. 2. Connect another single-mode, 9-micron fiber optic cable from port 6 of the bottom switch to the other connection point. Other Transport Modes Data Replication Manager uses other long distance transport modes. For connection information, refer to our website at: http://www.compaq.
Configuring a Data Replication Manager Solution 4–17 Configure the Host Install the Host Bus Adapters and Drivers To run Data Replication Manager, you should have two host bus adapters installed in each host system. If you are using Windows NT, you will need to change the default Topology value from loop to switch. Follow the procedures outlined in the next section. Refer to the KGPSA-BC PCI-to-Optical Fibre Channel Host Bus Adapter User’s Guide for installation information. 1. Access REGEDT32.
4–18 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 3. You can set the password and allow client access via the Secure Path Agent Configuration. NOTE: Compaq recommends that you set both the fully qualified and unqualified DNS names as valid, authorized clients. 4. Reboot the host. Install SWCC (optional) Detailed information about SWCC can be found in the StorageWorks Command Console Getting Started Guide.
Configuring a Data Replication Manager Solution 4–19 4. Verify that the connection between the host and the switch has been made by entering this CLI command: SHOW CONNECTIONS NOTE: You can also verify that a connection has been made by looking for the illuminated green LED that flashes on the switch ports. 1 2 CXO7088A Figure 4–5.
4–20 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 5. For OpenVMS systems, change the operating system for each connection. Enter the following CLI command: SET !NEWCONnn OPERATING_SYSTEM = VMS 6. Verify that the connection between the host and the switch has been made by entering this CLI command: SHOW CONNECTIONS NOTE: You can also verify that a connection has been made by looking for the illuminated green LED that flashes on the switch ports.
Configuring a Data Replication Manager Solution !NEWCONxx Worldwide Name Host Name 4–21 Path Number Figure 4–6.
4–22 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Configure the Controllers at the Initiator Site Pre-Configure Procedure Prior to configuring the controllers at the initiator site, be sure to follow these preparatory steps: ■ Identify the worldwide name on the host bus adapters. ■ Establish the name that you will assign to the initiator site. This name should be different from the one you assigned to the target.
Configuring a Data Replication Manager Solution 4–23 You will see a display similar to the following: Controller: HSG80 ZG8nnnnnnn Software V85P, Hardware E03 NODE_ID = nnnn-nnnn-nnnn-nnnn ALLOCATION_CLASS = 0 SCSI_VERSION = SCSI-2 Not configured for dual-redundancy Controller misconfigured -- other controller present Device Port SCSI address 7 Time: NOT SET Command Console LUN is disabled Host PORT_1: Reported PORT_ID = nnnn-nnnn-nnnn-nnnn PORT_1_TOPOLOGY = OFFLINE (offline) Host PORT_2: Reported PORT_ID
4–24 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 12. Once the worldwide name has been located, assign it to the controller using the following CLI command: SET THIS NODE_ID=node_ID checksum The display should reflect the following: Warning 4000: A restart of parameters modified %CER--HSG80> --09-FEB-1999 Restart of this controller this controller is required before all the will take effect 10:07:54-- Restart of this controller required required 13.
Configuring a Data Replication Manager Solution 4–25 The output will show that the controllers have been configured to support multiple bus failover mode: Controller: HSG80 ZG8nnnnnnn Software V85P, Hardware E03 NODE_ID = nnnn-nnnn-nnnn-nnnn ALLOCATION_CLASS = 0 SCSI_VERSION = SCSI-2 Configured for MULTIBUS_FAILOVER with ZG8nnnnnnn In dual-redundant configuration Device Port SCSI address 7 Time: NOT SET Command Console LUN is disabled NOTE: These settings will automatically be applied to controller B.
4–26 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 21.
Configuring a Data Replication Manager Solution NOTE: It may take up to five minutes after controller restart to check cache. The controllers will reject this command until cache check is complete. If this command is rejected, don’t restart the controllers. Wait a few minutes, then retry. 25. After the controllers restart, issue the following CLI command to confirm that mirrored write-back cache is enabled: SHOW THIS_CONTROLLER Notice that mirrored write-back cache is now set: .
4–28 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 29. You are now ready to enable Data Replication Manager. Use the following CLI command: SET THIS_CONTROLLER REMOTE_COPY=InitiatorName Example: SET THIS_CONTROLLER REMOTE_COPY=BuildngA NOTE: Be sure to specify a meaningful InitiatorName. Do not use “local” and “remote”; these are reserved keywords. The name can be up to eight characters and must be unique to all of your controllers.
Configuring a Data Replication Manager Solution 1. 4–29 Disable access on all units with this command: SET Unit DISABLE_ACCESS_PATH=ALL NOTE: Be sure to issue this command for all units. 2.
4–30 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Cabling the Initiator Site Connect Fiber Optic Cables Between the Controllers and Switches To better understand which ports you will be instructed to connect the cables to, Figure 4–7 shows the port locations on the switch. CXO7085A Figure 4–7. Port Locations 1. Connect a multi-mode, 50-micron fiber optic cable from port 1 of the top controller to port 2 of the top Fibre Channel switch. 2.
Configuring a Data Replication Manager Solution 4–31 2 1 3 4 CXO7089A Figure 4–8. Cabling between the controllers and switches Connect the Initiator Site to the External Fiber Link Locate the connection points at the initiator site that link the initiator site to the target site. Look for either a fiber optic cable connector or a patch panel where you can insert a cable. Long Wave GBICs 1. Connect a single-mode, 9-micron fiber optic cable from port 6 of the top switch to one connection point. 2.
4–32 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 2 1 3 1 CXO7090A Figure 4–9.
Configuring a Data Replication Manager Solution 4–33 2. Verify that the target has access to the initiator controller with this CLI command: SHOW CONNECTIONS 3. The target units will need to allow access to the controllers at the initiator site.
4–34 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide You will see %EVL display that includes your remote copy set information: %EVL--Initra > --13-JAN-1946 05:01:56 (time not set)-- Instance Code: 0E010064 Template: 144.(90) Power On Time: 0. Years, 36. Days, 6. Hours, 45. Minutes, 22.
Configuring a Data Replication Manager Solution 4–35 Creating Log Units and Association Sets (optional) In this example, hypothetical disks 50100 and 60100 are used as the mirrorset for the log disk. The log unit is D10. The association set name is AS_D1. The association set is using remote copy set name RC_D1. Creating a Log Unit 1. Create a mirrorset for the log disk by issuing the following CLI command: ADD MIRRORSET MirrorsetName DiskName Example: ADD MIRR MIR_D1LOG DISK50100 DISK60100 2.
4–36 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Creating Association Sets and Assigning a Log Unit 1. Create an association set with the following CLI command: ADD ASSOCIATIONS AssociationSetName RemoteCopySetName Example: ADD ASSOCIATIONS AS_D1 RC_D1 NOTE: Additional members can be added to the association set by issuing the following CLI command: SET AssociationSetName ADD=RemoteCopySetName 2.
Configuring a Data Replication Manager Solution 4–37 5. To assign the log unit to the association set, use the following CLI command: SET AssociationSetName LOG_UNIT = D10 Example: SET AS_D1 LOG_UNIT = D10 6.
4–38 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 3. Using the String Editor, make sure the value of Topology in the string is equal to 1. This will tell the driver to operate in a Fibre Channel switched environment. 4. Exit the Registry Editor. Install Secure Path (NT only) For installation information, refer to the StorageWorks Secure Path for Windows NT, A High Availability MultiPath Solution, Installation Guide. 1.
Configuring a Data Replication Manager Solution 4–39 The host is now connected to the initiator site via the multi-mode, 50-micron fiber optic cables. Your cabling should appear as it does in Figure 4–10. NOTE: You may choose any available port to connect your cables to, but you must maintain that identical scheme at the target site.
4–40 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide CXO7092A Figure 4–11. Data Replication Manager cabling at initiator and target sites 3. Verify that the connection between the host and the switch has been made by entering this CLI command: SHOW CONNECTIONS NOTE: You can also verify that a connection has been made by looking for the illuminated green LED that flashes on the switch ports.
Configuring a Data Replication Manager Solution 4–41 Rename the Host Connections To better identify which hosts you are working with, Compaq recommends that you rename the prompts that are reserved for the host names. You will need to change the !NEWCON prompt to a meaningful host name. Each host-based adapter will appear as a connection. An individual host-based adapter can be identified by its worldwide name that you recorded in the Getting Started Chapter and appears in the connection description.
4–42 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Configuring a Data Replication Manager Solution 4–43 b. Select Save and insert a floppy as requested. NOTE: It is recommended that two copies of the saved configuration be created and maintained at both the initiator and target sites. This data will be used to restore a known configuration in the event of a site failover or failback. 5. You are now ready to run Secure Path Manager, which can be found in the Start/Programs/StorageWorks/Secure Path Manager path.
4–44 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 2. Start a terminal emulator session. On Windows NT, use the HyperTerminal emulator. Settings to be used are: 9600 baud, 8 bits, No parity, 1 stop bit, XON/XOFF. 3. Select Capture Text from the Transfer menu. The Capture Text dialog box appears. 4. In the c:\field, type initiator.txt or target.txt. 5. Click START. SHOW Commands 1.
Configuring a Data Replication Manager Solution 4–45 Cache is GOOD No unflushed data in cache CACHE_FLUSH_TIMER = DEFAULT (10 seconds) Mirrored Cache: 256 megabyte write cache, version 0012 Cache is GOOD No unflushed data in cache Battery: NOUPS FULLY CHARGED Expires: Extended information: Terminal speed 9600 baud, eight bit, no parity, 1 stop bit Operation control: 00000000 Security state code: 75184 Configuration backup disabled 2.
4–46 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Configuring a Data Replication Manager Solution 4–47 To see information for all units configured to the controller, issue the following CLI command: SHOW UNITS FULL You will see a display similar to the following for each unit: D2 DISK10100 BuildngA\RC2 LUN ID: 6000-1FE1-0001-3AE0-0009-9141-6136-0045 NOIDENTIFIER Switches: RUN NOWRITE_PROTECT READAHEAD_CACHE READ_CACHE WRITEBACK_CACHE MAXIMUM_CACHED_TRANSFER_SIZE = 1 Access: BuildngBA,BuildngBB,BuildngBC,BuildngBD,HOSTA1,HOSTA2 State: ONLINE to t
Chapter 5 Managing Site Failover and Failback Procedures This chapter describes how to manage Failover and Failback for your Data Replication Manager solution.
5–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Managing Failover and Failback Procedures The procedures below outlines how to power on and power off the storage subsystem after it has been configured. Power Up CAUTION: Compaq recommends that you power up the controllers and switches at the target site before applying power to the initiator site. Powering up in the wrong sequence may cause incorrect configurations.
Managing Site Failover and Failback Procedures 5–3 Site Failover If the initiator site is no longer available, or if there is anticipated down time that will prevent operation there, you must decide whether or not to perform a site failover. Performing a failover will enable the target site to assume the role of the initiator and access data until the problem is resolved.
5–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Failback During Failover, the remote copy sets on the target site are in a “copy ready” state, waiting for the initiator site to become available. When the new initiator site has been established or the original one has been restored, site operation can resume after a failback procedure has been performed.
Managing Site Failover and Failback Procedures BuildngA 5–5 BuildngB Host A BuildngA Host B BuildngB CXO7172A Figure 5–1. Data Replication Manager basic configuration This chapter demonstrates example failover and failback procedures using a fictional Building A as the initiator site and Building B as the target site. The examples described will failover from Building A to Building B and then failback from Building B back to Building A.
5–6 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Table 5–2 DRM Planning Considerations 1. If you lose intersite connections, and both the initiator and target configurations are functional, the system administrator must determine which site to use. An intersite connection could include hardware or fiber-related equipment either at the initiator or target locations. 2.
Managing Site Failover and Failback Procedures 5–7 Table 5–2 DRM Planning Considerations (Continued) 6. This applies whether you are operating at the initiator site during normal operations or at the target site after a failover. 7. To clear this condition you must repair or replace the failed controllers, then: ❏ Fix the extended link condition or ❏ Remove the remote copy sets 8. After these conditions are met, both controllers must be restarted to clear the faulted state 9.
5–8 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide NOTE: Association Sets do not need to be deleted. 5. Disable host access to the units by using the following CLI command: SETUnitName DISABLE=(InitiatorHostConnectionNamex,InitiatorHostConnectionNamey) IMPORTANT: Do not disable access to the target connection. Repeat this step for all units. 6.
Managing Site Failover and Failback Procedures 5–9 If you made the decision to remove remote copy set targets, go to Step 3. If you made the decision to NOT remove remote copy set targets, go to Step 5. 3. To remove the targets, use the following CLI command: SET RemoteCopySetName REMOVE=InitiatorRemoteCopyName\UnitNumber Example: SET rcs1 REMOVE=buildngA\d1 4. Repeat this step for all remote copy sets. NOTE: The InitiatorRemoteCopyName is the remote copy name of the original initiator.
5–10 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide NOTE: Be sure that the units you see (listed under “Initiator State”) are at the target site and not the initiator site units. 4. To verify that the target hosts can connect to the LUNs, use this command: SHOW UNITS FULL In the Access field of the display, all units should show that the target hosts are enabled. This should also show the initiator controller connections. 5.
Managing Site Failover and Failback Procedures 5–11 Target Site Simple Failback Procedure 1. To see the operation mode of the remote copy sets, type the following CLI command: SHOW REMOTE_COPY_SETS FULL 2. If you made the decision to remove the remote copy set targets, the targets should be added at this time, using the following CLI commands: SET RemoteCopySetName ADD=InitiatorRemoteCopyName\UnitNumber Example: SET rcs1 ADD=buildngA\d1 Repeat this step for all remote copy sets.
5–12 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Repeat this procedure for each association set. 8. Move the remote copy sets to the new initiator using the following CLI command: SET RemoteCopySetName INITIATOR=InitiatorRemoteCopyName\UnitName NOTE: If after issuing this command for one of the Remote Copy Sets you get the error message: Error: Rem Cp Set specified is currently in a transient state, wait a few seconds and try again.
Managing Site Failover and Failback Procedures 5–13 6. For OpenVMS, if you have shut down the host, boot the host at this time. Booting the host enables OpenVMS to recognize the drives. If you did not shut down the host, use the following command from a privileged account to enable OpenVMS to recognize the drives: MCR SYSMAN I0 AUTOCONFIGURE/LOG Unplanned Failover Use the procedures outlined in this section with the Full Failback or New Hardware Failback procedures.
5–14 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 4. To remove the targets use the following CLI command: SET RemoteCopySetName REMOVE=InitiatorRemoteCopyName\UnitNumber Example: SET rcs1 REMOVE=buildngA\d1 Re-create association sets that are on the initiator. Repeat this step for each association set. NOTE: Refer to the configuration chapter for information on how to create association sets. 5.
Managing Site Failover and Failback Procedures 5–15 Full Failback Status Comparison Before performing the Full Failback Procedure, verify that your initiator controller configuration is the same as your target controller configuration. If write history logging was enabled at the initiator before the failover, and remote copy sets were in asynchronous operation mode, then write history logging will not be enabled at the target site.
5–16 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Managing Site Failover and Failback Procedures 5–17 Extended information: Terminal speed 9600 baud, eight bit, no parity, 1 stop bit Operation control: 00000000 Security state code: 75184 Configuration backup disabled 2.
5–18 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Managing Site Failover and Failback Procedures 5–19 Full Failback Procedure Preparing the Initiator Site 1. Shut down the initiator host if it is still up and running. (This is not necessary for OpenVMS.) 2. Both controllers on the initiator site must be restarted after the site failover has taken place. Do this with the following CLI commands: RESTART OTHER_CONTROLLER RESTART THIS_CONTROLLER 3. The connection between the sites must be broken.
5–20 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 7. Check to see if the initiator controller has access to the target remote copy sets by typing the following CLI command: SHOW UNITS FULL 8.
Managing Site Failover and Failback Procedures 5–21 IMPORTANT: You must wait for normalization on all remote copy sets to complete before you can proceed. 4. Shut down the target host. 5. Disable access to the target hosts by using the following CLI command: SET UnitName DISABLE=(TargetHostConnectionNamex,TargetHostConnectionNamey) 6. Delete association sets by using the following CLI command: DELETE AssociationSetName 7.
5–22 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide IMPORTANT: You must wait for normalization on all remote copy sets to complete before you can proceed. 3. Re-enable logging or failsafe, if desired. To set failsafe, use the following CLI command: SET RemoteCopySetName ERROR_MODE = FAILSAFE Failsafe cannot be set if the remote copy set is within an association set that is to be used for write history logging.
Managing Site Failover and Failback Procedures 5–23 2. Add targets to the remote copy sets by issuing the following CLI commands: SET RemoteCopySetName ADD = InitiatorRemoteCopyName\UnitName Issue this command for every remote copy set that does not have a target. NOTE: You must wait for normalization on all remote copy sets to complete before you can proceed. 3.
5–24 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide New Hardware Failback Procedure Use the New Hardware Failback Procedure when the initiator site is not intact and you are working with all new hardware that is not configured. Terminal Emulator Session 1. Use a laptop computer or another computer to connect a serial cable between the COM port on that machine and the corresponding serial port on the HSG80 controllers. 2.
Managing Site Failover and Failback Procedures Address 5–25 = 220313 REMOTE_COPY = BuildingB Cache: 256 megabyte write cache, version 0012 Cache is GOOD No unflushed data in cache CACHE_FLUSH_TIMER = DEFAULT (10 seconds) Mirrored Cache: 256 megabyte write cache, version 0012 Cache is GOOD No unflushed data in cache Battery: NOUPS FULLY CHARGED Expires: Extended information: Terminal speed 9600 baud, eight bit, no parity, 1 stop bit Operation control: 00000000 Security state code: 75184 Configuration
5–26 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide 3. To see information for all remote copy sets known to the controller pair, issue the following CLI command: SHOW REMOTE_COPY FULL You should see a display similar to that in Example Display 3 for each remote copy set.
Managing Site Failover and Failback Procedures 5–27 Example Display 4 D2 DISK10100 LATHE\RC2 LUN ID: nnnnnnnnnnnnnnnnnnnnnn NOIDENTIFIER Switches: RUN NOWRITE_PROTECT READAHEAD_CACHE READ_CACHE WRITEBACK_CACHE MAXIMUM_CACHED_TRANSFER_SIZE = 1 Access: LATHEA, LATHEB, LATHED, HostCon_1, HostCon_2 State: ONLINE to this controller Not reserved PREFERRED_PATH = OTHER_CONTROLLER Target NORMAL Size: 17769177 blocks Geometry (C/H/S): ( 5258 / 20 / 169 ) 5.
5–28 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Failback Procedures Preparing the Initiator Site 1. Shut down the initiator host(s) if it is still up and running. (This is not necessary for OpenVMS.) 2. Manually reconfigure the controllers, but do not re-create the original remote copy sets. This procedure includes the following steps: a. Set node ID and checksum (this information can be found on the original initiator BA370 cab).
Managing Site Failover and Failback Procedures 5–29 4. Enable connection to fabric by using the following CLI commands: SET THIS (and OTHER) PORT_1_TOPOLOGY=FABRIC SET THIS (and OTHER) PORT_2_TOPOLOGY=FABRIC Preparing the Target Site and Creating Connections from the Initiator to the Target 1.
5–30 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Creating Connections from the Initiator Site to the Target 1. Issue the following CLI command: ADD REMOTE_COPY_SETS RCS199 D199 TargetRemoteCopyName\D199 NOTE: This command will fail, but creates and names the connections appropriately. 2.
Managing Site Failover and Failback Procedures 5–31 Repeat this procedure for all association sets. 7. Shut down the target HSG80 controllers (in this order) with the following CLI commands: SHUTDOWN OTHER_CONTROLLER SHUTDOWN THIS_CONTROLLER Returning Control to the Initiator 1. The connection between the sites must be broken. Issue the following CLI commands: SET THIS_CONTROLLER PORT_2_TOPOLOGY = OFFLINE SET OTHER_CONTROLLER PORT_2_TOPOLOGY = OFFLINE 2.
5–32 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide Initiator Site Clean-Up 1. Re-enable logging or failsafe, if desired. To set failsafe issue the following CLI command: SET RemoteCopySetName ERRORMODE=FAILSAFE NOTE: Failsafe cannot be set if the remote copy set is within an association set that is to be used for write history logging. To re-enable logging, create the log unit, then create the association set and assign the log unit to the association set.
Managing Site Failover and Failback Procedures 5–33 8. For OpenVMS, if you have shut down the host, boot the host at this time. Booting the host enables OpenVMS to recognize the drives.
5–34 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Chapter 6 Troubleshooting This chapter describes possible failure modes of a Data Replication Manager solution. Isolation of errors and detailed error analysis require a complete understanding of how a Data Replication Manager subsystem operates. While it is not possible to document every error and failure condition, key failures of the Data Replication Manager subsystem and its components are discussed.
6–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Troubleshooting 6–3 Dual Redundancy During Failback The failback sequence is a scheduled event based upon the configuration at the failback site. The HSG80 array controller requires that a viable dual-redundant subsystem be available before a failback can take place. Failback to a single-controller configuration is not supported. Failsafe Lock Management If failsafe mode is set for a remote copy set it can become failsafe locked if a unit fails or the target becomes inaccessible.
6–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide ■ If a remote copy set target member fails, a write issued to that remote copy set will cause a write failure at the target. The target member will be removed, and the remote copy set will be put in failsafe lock condition. If you wish to continue operation at the initiator site, be sure to change the remote copy set error mode to normal before proceeding.
Troubleshooting 6–5 Component Failures The service and maintenance of a Data Replication Manager solution is based on failure of subsystem components. When a component fails, you must determine the cause of the failure, the most appropriate workaround to eliminate down time, and the best course of action to resolve the problem.
6–6 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide SWCC Failure SWCC notifies the user of any component loss in the system via an active SWCC Client Graphical User Interface (GUI). This GUI window on the command console monitor is a graphical representation of the controllers and their physical and logical storage elements. SWCC periodically queries the controllers for status. Clients connected to the GUI .
Troubleshooting 6–7 Failure Modes of a DT System in Normal Operation Table 6–1 details the failure modes of a DT system operating in normal mode. While this table concentrates on the major failure possibilities, keep in mind that there are several other combinations that may occur. In most cases, when there is a loss of a major component, a failover is necessary to continue operation.
6–8 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
Troubleshooting 6–9 Failure at Target Site after Failover After a failover has occurred, failures at the target site are detected the same as in a non-disaster tolerant state. Table 6-2 shows the possible failure modes at the target site, assuming that the initiator site is not available to failback to.
Glossary This glossary defines terms pertaining to the Data Replication Manager for the HSG80 running ACS V8.5P. It is not a comprehensive glossary of computer terms. ACS An abbreviation representing Array Controller software. See array controller software. adapter A hardware device that converts the protocol and hardware interface of one bus type to another without changing the function of the bus. AL_PA or ALPA A term used to express Arbitrated Loop Physical Address.
G–2 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide association sets An association set is a group of remote copy sets that share common attributes. Members of an association set can be configured to transition to the same state at the same time. An association set: ■ Shares the same log unit ■ Has its host access removed from all members when one member fails ■ Keeps I/O order across all members CLI commands available are ADD ASSOCIATIONS and SET associations.
Glossary G–3 block A stream of data stored on a disk or tape media and transferred and error-checked as a unit. In a disk drive, a block is also called a sector (the smallest collection of consecutive bytes addressable on a disk drive). In integrated storage elements, a block contains 512 bytes of data, error codes, flags, and the block address header. cache memory A portion of high-speed memory used as an intermediary between a data user and a larger amount of storage.
G–4 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide controller A hardware device that uses software to facilitate communications between a host and one or more storage devices organized in an array. The HS-series StorageWorks family of controllers are all array controllers. copying member In a mirrorset, a copying member is a container introduced to the mirrorset after it has been in use for some amount of time.
Glossary G–5 EMU An acronym for Environmental Monitoring Unit. A piece of hardware that provides increased protection against catastrophic failures. Some subsystem enclosures include an EMU which works with the controller to detect conditions such as failed power supplies, failed blowers, elevated temperatures, and external air sense faults. The EMU also controls certain cabinet hardware including DOC chips, alarms, and fan speeds. external cache battery See ECB.
G–6 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide fast failback A term representing the synchronization of the initiator site with the target during a planned failover of the initiator subsystem. The write operations are logged to the target site write history log, and during the fast-failback, the initiator site is updated from the write history log. See also mini-merge, unplanned failover, planned failover, write history logging.
Glossary G–7 FCC Class B This certification label appears on electronic devices that can be used in either a home or a commercial environment within the United States. FCP The mapping of SCSI-3 operations to Fibre Channel. FDDI Fiber Distributed Data Interface. An ANSI standard for 100 megabaud transmission over fiber optic cable. FD SCSI The fast, narrow, differential SCSI bus with an 8-bit data transfer rate of 10 MB/s. See also FWD SCSI and SCSI.
G–8 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide GLM An abbreviation for the Gigabit Link Modules used in Fibre Channel long distance applications. The GLMs provide the ability to increase the fiber optic cable transmission distances from10 KM to ??? hard address The ALPA which an NL_Port attempts to acquire during loop initialization. heterogeneous host support Also called noncooperating host support.
Glossary G–9 logical unit A physical or virtual device addressable through a target ID number. LUNs use their target’s bus connection to communicate on the SCSI bus. Logical Unit Number Abbreviated LUN. A value that identifies a specific logical unit belonging to a SCSI target ID number. A number associated with a physical device unit during a task’s I/O operations. Each task in the system must establish its own correspondence between logical unit numbers and physical devices.
G–10 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide NL_port A port attached to a node for use in all three topologies. network A data communication, a configuration in which two or more terminals or devices are connected to enable information transfer. Non-L_Port A Node of Fabric port that is not capable of performing the Arbitrated Loop functions and protocols. N_Ports and F_Ports loop-capable ports.
Glossary G–11 PCM Polycenter Console Manager. PCMCIA An abbreviation for Personal Computer Memory Card Industry Association. An international association formed to promote a common standard for PC card-based peripherals to be plugged into notebook computers. A PCMCIA card is about the size of a credit card. It is used in the HSJ80 to load the controller software. See also program card, ACS. PCR An abbreviation used to express peak cell rate.
G–12 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide port_name A 64-bit unique identifier assigned to each Fibre Channel port. The Port_Name is communicated during the logon and port discovery process. preferred address The AL_PA which an NL_Port attempts to acquire first during initialization. private NL_Port An NL_Port which does not attempt login with the fabric and only communicates with NL_Ports on the same loop.
Glossary G–13 QoS A term used to express Quality of Service in an ATM network. Each virtual connection in an ATM network is set to a service category. The performance of the connection is measured by the established QoS parameters (outlined by the ATM forum). Performance issues include data, rate, cell loss rate, cell delay, and delay variation (jitter).
G–14 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide SCSI An acronym for Small Computer System Interface: 1. An American National Standards Institute (ANSI interface standard defining the physical and electrical parameters of a parallel I/O bus used to connect initiators to devices. 2. A processor-independent standard protocol for system-level interfacing between a computer and intelligent devices including hard drives, floppy disks, CD-ROMs, printers, scanners, and others.
Glossary G–15 synchronous mode A mode of operation of the remote copy set whereby the data is written simultaneously to the cache of the initiator subsystem and the cache of the target subsystem. The I/O completion status is not sent until all members of the remote copy set are updated. See also asynchronous mode. this controller The controller that is serving your current CLI session through a local or remote terminal. See also other controller. TILX Tape inline exerciser.
G–16 Compaq StorageWorks Data Replication Manager HSG80 ACS V8.5P Operations Guide VCI An abbreviation used to express virtual channel identifier. The VCI is the field of the cell header that stores the virtual channel address. VPI An abbreviation used to express virtual path identifier. The VCI is the field of the cell header that stores the virtual path address.
I–1 Index Switch. See Fibre Channel gigabit switch Symbols %CER. See CLI Event Report %EVL. See Event Log %LFL. See Last Failure Log A ACS.
I–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
I–3 Failures at target site after failover 6–9 both fiber optic cables or switches 6–6 component 6–5 controller 6–5 network 6–7 notification 6–5 StorageWorks Command Console 6–6 Fiber optic cable 3–3 50 micron 3–4, 4–18, 4–38 9 micron 3–4 connecting between initiator controllers and switches 4–30 connecting between target controllers and switches 4–14 connecting hosts and switches at initiator site 4–38 connecting hosts and switches at target site 4–18 connecting target site to external fiber link 4–15, 4–
I–4 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.
I–5 worldwide name location 4–8, 4–23 SWCC. See StorageWorks Command Console Switch.
