HP StorageWorks B-Series remote replication solution best practices guide Part number: 5697-6731 First edition: June 2007
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Contents About this guide . . . . . . . . . . . . . . . . . . . . . . . . . . Intended audience . . . . . . . Related documentation . . . . . Document conventions and symbols Rack stability . . . . . . . . . HP websites . . . . . . . . . . Documentation feedback . . . . 1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Tools for managing and monitoring the replication network HP StorageWorks Continuous Access Solution testing with EVA workloads HP StorageWorks B-Series tools . . WAN analysis tools . . . . . Procedure description . . . . EVA . . . . . . . . Performance Estimator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figures 1 ..Simplest Meta SAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2 ..Meta SAN with four edge fabrics . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 ..Edge fabrics #1 logical view of Meta SAN . . . . . . . . . . . . . . . . . . . . 19 4 ..Simplest Meta SAN with FCIP . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5 ..Dedicated backbone fabric Meta SAN . . . . . . . . . . . . . . . . . . . . . . 6 ..Dedicated backbone fabric with common devices . . . . . .
Tables 1 ..Document conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 ..Required software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3 ..Required hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4 ..Optional components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5 ..Inter-site link parameters 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 ..Backbone fabric vs. edge fabric limitations 6 . . . .
About this guide This guide provides information about: • Deployment of the HP disaster recovery/remote replication B-series solution across the HP StorageWorks Enterprise Virtual Array (EVA) family • Design considerations specific to the HP StorageWorks B-Series SAN Infrastructure and HP StorageWorks Continuous Access EVA • Deployment of the HP StorageWorks 400 Multi-Protocol Router and/or Multi-Protocol Router blade in the HP StorageWorks SAN Director 4/256 • Tools for managing and monitoring the network
Convention Element • Commands, their arguments, and argument values Monospace, italic text • Code variables • Command variables Monospace, bold text Emphasized monospace text WARNING! Indicates that failure to follow directions could result in bodily harm or death. CAUTION: Indicates that failure to follow directions could result in damage to equipment or data. IMPORTANT: Provides clarifying information or specific instructions. NOTE: Provides additional information.
• http://www.hp.com/support/manuals • http://www.hp.com/support/downloads Documentation feedback HP welcomes your feedback. To make comments and suggestions about product documentation, please send a message to storagedocsFeedback@hp.com. All submissions become the property of HP.
About this guide
1 Overview This document describes how to deploy an HP disaster recovery/remote replication B-Series solution. It focuses on a replication solution using Continuous Access EVA and FCIP, and the deployment of the HP StorageWorks 400 Multi-Protocol Router and/or Multi-Protocol Router Blade in the HP StorageWorks SAN Director 4/256.
Overview
2 Hardware and software considerations HP StorageWorks storage arrays The HP StorageWorks Enterprise Virtual Array family (EVA) is designed for customers in the business-critical enterprise marketplace, offering a high performance, high availability virtual array storage solution. The EVA is designed for the data center where there is a critical need for improved storage utilization and scalability.
HP hardware Table 3 Required hardware Required hardware Hardware description HP StorageWorks B-Series SAN infrastructure—switches/directors The HP StorageWorks 400 Multi-Protocol Router/MP Router blade is compatible with all HP-supported B-Series SAN switches/directors, as specified in the HP StorageWorks SAN Design reference guide.
Solution components requirements and considerations This section highlights information to consider when building the data replication solution. HP StorageWorks 400 Multi-Protocol Router/MP Router blade • Use the MP Router blade, if there are available slots in the HP StorageWorks 4/256 SAN Director; otherwise, use the standalone 400 Multi-Protocol Router. See the HP StorageWorks SAN Design reference guide at http://www.hp.
HP StorageWorks Continuous Access software HP StorageWorks Continuous Access mandates certain inter-site link parameters in order to have optimal performance. Table 5 Inter-site link parameters Description Specification IP Bandwidth Must be dedicated to the Continuous Access storage replication function. 1 Maximum number of DR Groups See the tables in the HP StorageWorks SAN design reference guide for minimum supported bandwidth based on the average packet-loss ratio and one-way inter-site latencies.
3 Solution setup overview Solution configuration concepts B-Series fibre channel-to-fibre channel routing FC-to-FC Routing is a technology that logically connects physically separate fabrics (SAN islands) to enable selective shared access to resources from any fabric, with the benefits of administration and fault isolation of separately managed fabrics. FC routing does not merge the fabrics, so the issues associated with merging fabrics, such as Domain ID overlaps and Zoning conflicts, do not apply.
Figure 1 Simplest Meta SAN Backbone fabric The backbone fabric is the functional element that makes the logical connection between edge fabrics, or between the backbone fabric and an edge fabric. The backbone fabric, at a minimum consists, of at least one MP Router, but can contain more than one MP Router and standard FC switches in the backbone fabric. MP routers and FC switches in the backbone fabric are linked via a standard ISL that is no different from any other FC fabric.
NOTE: LSAN zones in the backbone fabric with a 2 Gb MP Router are not supported. Edge fabric view of a Meta SAN To the edge fabric, the MP Router’s EX_Port looks like any other FC switch in the edge fabric. However, the EX_Port blocks the edge fabric from seeing the real topology of the backbone fabric or any switches in any other edge fabrics.
NOTE: The edge fabric #3 is not presented to edge fabric #1 because, in the example, no LSAN zones for that fabric exist. For this example, if a FabricShow command is executed on any FC switch in edge fabric #1, it lists all physical FC switches in edge fabric #1 and three other logical switches: one logical switch for the backbone fabric and one for each edge fabric that has devices routed to edge fabric #1.
Backbone fabric limitations The backbone fabric is the functional element that makes the logical connection between edge fabrics, or between the backbone fabric and an edge fabric. There are some limitations in terms of the number of FC Routers, FC switches and devices that are supported in the backbone fabric. Table 6 Backbone fabric vs. edge fabric limitations FOS Version FOS 5.1 FOS 5.
Figure 5 Dedicated backbone fabric Meta SAN Utilizing a Dedicated Backbone as shown in Figure 5 can solve the backbone fabric scaling and FCIP IP network issues. By implementing a dedicated backbone fabric, no existing production fabric has the backbone fabric scaling limitations imposed on it, and generally the number of FC switches and devices on this dedicated fabric are smaller and within the current limitations.
• 6–fabric architecture: provides the highest availability level By using the B-Series directors and standalone switches capabilities, and the combination of Fibre Channel routing, switching, and SAN extension, the physical configuration can be reduced to fewer elements to drive additional simplification and ease of maintenance. Continuous Access EVA configurations The 400 MP Router and MP Router blade support the HP standard Continuous Access EVA replication configurations.
Figure 8 Continuous Access EVA 4–fabric FCIP router configuration The design of a Meta SAN using FCIP needs to balance the scaling limitations of the backbone fabric with the disruptions an IP network can have on the edge fabric. There are two alternative solutions to overcome these two issues. The traditional solution has been to create a dedicated replication fabric or fabrics as shown in the five-fabric, and six-fabric implementations in Figure 9 and Figure 10.
Figure 9 Continuous Access EVA five-fabric FCIP-router configuration Figure 10 shows a combination of a 4-port EVA 8000 and 2-port EVA 6000/5000/4000/3000 configuration of a Continuous Access six-fabric solution. In this configuration, two dedicated fabrics are implemented for replication traffic. It eliminates the fabric merging issue with a traditional FCIP implementation and the scaling limitation of an integrated backbone fabric solution.
Figure 10 Continuous Access EVA 6–fabric FCIP router configuration Figure 11 shows a typical 4-port EVA 8000 configuration of a Continuous Access six-fabric with dedicated backbone fabrics LSAN replication zones solution. In this configuration, half the EVA controller ports are connected to each of the dual redundant fabrics for each site.
Figure 11 Continuous Access EVA six-fabric FCIP-router with dedicated backbone fabrics configuration If your topology does not fit the sample configurations in this section, see the HP StorageWorks SAN design reference guide on the website http://www.hp.com/go/sandesignguide for configuration requirements and design considerations. Overall Setup Plan To set up Continuous Access replication from one B-Series fabric to another (FOS 5.2.
2. Use B-Series WANTOOLS facilities to discover the operational characteristics of the IP network you intend to use for Continuous Access replication. See Tools for managing and monitoring the replication network, page 37 for more information.
4 Solution setup Configuring FCIP on the HP StorageWorks 400 MP Router/MP Router blade Use the Web Tools interface to configure the FCIP connection between two geographically separate sites on a Wide Area Network (WAN). You can also use the command line interface with either direct console (serial) connection to the switch or through telnet sessions (see Configuring FCIP interfaces and tunnels on the HP StorageWorks 400 MP Router using CLI commands, page 47 in the Appendix.) Refer to the FOS 5.1.
5. Ensure that port ge0 is selected and click Edit Configuration to launch the GigE Port Configuration Wizard. 6. Click Next. The GigE Port # 0 Configuration window displays. 7. Click Add Interface, and enter the IP address and MTU size. Valid entries are 1500 and 2250. NOTE: Your network administrator will provide the MTU size. Table 7 FCIP configuration Examples GbE Port IP Address (local) IP Address (remote) Tunnel First Tunnel Ge0 10.0.10.1 10.0.10.2 0 8. Select Close > Next.
The FCIP Tunnel Configuration window displays. 12. Set the desired configuration parameters and click Next. NOTE: If you want to enable compression across the FCIP link, click the Enable Compression checkbox in the Tunnel Configurations window. Do not select the FastWrite checkbox as HP Continuous Access EVA uses other ways to do this. Since it is a hardware-enabled compression, HP recommends enabling compression. HP also recommends using committed tunnels. 13.
NOTE: Although not covered here, the procedures for the MP Router blades are identical, but some screen shots will differ slightly given the blade orientation in the director chassis. To start this procedure on a blade router, point your browser to the IP address of the Director. Configuring Fibre Channel routing (FCR) To configure the Fibre Channel routing using Web Tools: 1. Launch the FC routing module via the FCR button in the Switch View on the router.
NOTE: LSANs are set up the same way as other zones with the exception that the zone name starts with “LSAN_”. NOTE: The Share Devices wizard in Fabric Manager simplifies the process of setting up LSANs. See HP StorageWorks Fabric Manager, page 50 for details. 8. The ports need to be enabled to see the LSANs. From the router, launch Web Tools and select the port to launch the Port Administration window: a. Select the port and click Persistent Enable. b. Close the Port Administrations window. 9.
the array copies the data to the virtual disks in the destination DR group. Virtual disks in a DR group fail over together, share a write history log (DR group log), and preserve write order within the group. Virtual disks that contain data for one application must be in one DR group. For optimum failover performance, limit the virtual disks in a DR group to as few as possible, and do not group virtual disks that are assigned to separate applications.
storage administrator is unaware of the outage, unable to respond or not present - because Cluster Extension EVA™ requires no server reboots or LUN presentation/mapping changes during failover. HP StorageWorks Cluster Extension EVA™ software is an integrated solution that provides protection against system downtime with automatic failover of application services and read/write enabling of remotely mirrored mid-range storage over metropolitan distances.
Solution setup
5 Tools for managing and monitoring the replication network Sizing link bandwidth requirements for remote replication is critical in meeting customer’s expectations. This section includes tools that can be used for estimating the effects of inter-site latency as well as determining the characteristics of the inter-site link.
Figure 12 HP StorageWorks Continuous Access EVA Replication Performance Estimator-V3 Solution testing with EVA workloads During acceptance testing and post installation, it is very important to monitor the network under a variety of representative Continuous Access EVA workloads before placing the system in production. Some or all of these tests should be run concurrently. Suggested workloads include the following: • Full DR Group copies (normalization of volumes).
• portcmd ipperf—Characterizes end-to-end IP path performance between a pair of B-Series FCIP ports. The path characterization elements include: • Bandwidth—Total packets and bytes sent. Bytes/second estimate will be maintained as a weighted average with a 30 second sampling frequency and also as an average rate over the entire test run. • Loss—Estimate is based on the number of TCP retransmits (assumption is that the number of spurious retransmits is minimal).
5. Using the output from these commands, the user has data that can be evaluated and used to guide the configuration of the FCIP tunnel. CLI syntax portcmd ping: Pings a destination IP address from one of the source IP interfaces on the GbE port.
Specifies the display/ refresh interval in seconds. Default: 30 sec -p port Specifies the TCP port number for the listener end-point. Default: 3227 -t running_time Specifies how long to run the test, in seconds. Default: run forever -z size Specifies the default packet size in bytes. Default: 64 bytes Examples 1. To verify if packets can be sent to the destination IP address, enter: portcmd --ping 4/ge0 -s 192.168.100.50 -d 192.168.100.40 2.
Executing portshow fciptunnel 8/ge0 0 −params displays the following output: 42 Tools for managing and monitoring the replication network
B-Series remote replication solution 43
Tools for managing and monitoring the replication network
6 Related information This document covers FCIP disaster recovery solutions using the B-Series components. However, additional technologies are also supported. These include using native Fibre Channel with WDM technology, and Continuous Access XP. Both of these technologies are supported with the B-Series components.
Related information
7 Appendix: Configuring FCIP interfaces and tunnels on the HP StorageWorks 400 MP Router using CLI commands This section is for expert users. Command procedure description 1. The user will use a telnet session to connect (login) to the local and remote B-Series routers. 2. Ensure that both the FC and FCIP ports are disabled during configuration operations. This prevents unintended fabric merges between local and remote fabrics. 3. By default, virtual ports are created as VE_Ports.
portcfg Configures the FCIP interfaces and tunnels. ipif: Configure IP interface entries Usage portcfg ipif [slot/][ge]port args Arguments create ipaddr netmask mtu_size Creates IP interfaces delete ipaddr Deletes IP interfaces. iproute: Configure IP route entries Usage portcfg iproute [slot/][ge]port args. Arguments create ipaddr netmask gateway_router metric Creates IP routes. delete ipaddr netmask Deletes IP routes. Usage portcfg fciptunnel [slot/][ge]port args [optional_args].
-r retransmissions Specifies the maximum retransmissions. Retransmissions values are 1 to 8; default is 8. If tape pipelining is enabled, the default value is calculated based on the minimum retransmit time to ensure that tcp connection does not timeout before the host times out. If the user changes this value, the value specified must be greater than the calculated value. -s Disables selective acknowledgement code (SACK) on the tunnel specified.
Disable (0) or Enable (1) selective acknowledgement (SACK) on the existing tunnel. -t 0|1 Disable (0) or Enable (1) tape pipelining NOTE: Some of the optional portcfg command settings are not compatible with the HP StorageWorks Continuous Access EVA product. Examples 1. To configure a VEX_Port, enter: portcfgvexport 8/18 -a 1 -f 2 -d 220 2. To create an IP interface, enter: portcfg ipif ge0 create 192.168.100.50 255.255.255.0 1500 Verify the created IP interface: portshow ipif ge0 3.
2. Select Tasks > Device Sharing and Troubleshooting > Share Devices to launch the Share Device wizard. 3. Click Next. The Select Devices to Share window displays. 4. Enter the logical SAN (LSAN) name. In this example, the LSAN name is LSAN_CA_Replication; the local managed fabric Switch115 is where the first aliases containing device port WWNs are selected from. The ports include the host port where Command View is run, and port number 4 from the EVA 8000 top and bottom controllers.
7. Select Finish > Yes > Yes. The LSAN is created. Fabric Manager distributes the LSAN definitions to both Fabrics. This process may take a few minutes, depending upon if the routed fabrics are local or across the WAN. 8. Select OK > Close to close the wizard. Viewing LSANS using Fabric Manager • Choose an edge fabric and select Tasks > Device Sharing and Troubleshooting > Show LSAN view. The devices in the LSAN LSAN_CA_Replication display.
