Compellent Best Practices with Site Recovery Manager 1.0

Compellent Storage Center

VMware Site Recovery Manager 1.0 Best Practices

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Compellent Storage Center VMware Site Recovery Manager 1.0 Best Practices

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Contents

Contents ....................................................................................................................... 2

Disclaimers ........................................................................................................... 3 General Syntax ..................................................................................................... 3 Conventions .......................................................................................................... 3 Where to Get Help ................................................................................................ 4 Document Revision ............................................................................................... 4 Common Abbreviations ........................................................................................ 4

Overview ...................................................................................................................... 5 Prerequisites ......................................................................................................... 5 Intended audience ................................................................................................ 5 Introduction ........................................................................................................... 5

Setup Prerequisites ...................................................................................................... 6 Enterprise Manager .............................................................................................. 6 Storage Center...................................................................................................... 6 VMware ................................................................................................................. 6 Storage Replication Adapter (SRA) ...................................................................... 6

Site Recovery Manager Architecture ........................................................................... 7 Single Protected Site ............................................................................................ 7 Multiple Protected Sites ........................................................................................ 8

Enterprise Manager Configuration ............................................................................... 9 Data Collector Configuration ................................................................................. 9 Enterprise Manager Logins ................................................................................... 9 Configuring Replications ..................................................................................... 10 Saving Restore Points ........................................................................................ 10 Validating Restore Points ................................................................................... 11 Automatic Restore Point Saving Schedule ......................................................... 12

Site Recovery Manager Configuration ....................................................................... 13 Configuring the Array Managers ......................................................................... 13 Rescanning Arrays ............................................................................................. 15 Creating Protection Groups ................................................................................ 16 Modifying Protection Groups to Exclude Pagefile Volumes ............................... 16 Creating Recovery Plans .................................................................................... 17

Recovery Plan Execution ........................................................................................... 18 Testing a Recovery Plan ..................................................................................... 18 Running a Recovery Plan ................................................................................... 18 Failing Back to the Primary Site.......................................................................... 20

Additional Resources ................................................................................................. 21 Appendix A – Example Scripts ........................................................................... 22



Disclaimers Information in this document is subject to change without notice. © 2005 Compellent Technologies. All rights reserved. Reproduction in any manner without the express written permission of Compellent Technologies is strictly prohibited. Trademarks used in this text are property of Compellent Technologies, or their respective owners.

General Syntax Table 1: Document syntax

Item Convention

Menu items, dialog box titles, field names, keys Bold

Mouse click required Click:

User Input Monospace Font

User typing required Type:

Website addresses http://www.compellent.com

Email addresses [email protected]

Conventions

Note Notes are used to covey special information or instructions.

Timesaver Timesavers are tips specifically designed to save time or reduce the number of steps.

CautionCaution Caution indicates the potential for risk including system or data damage.

WarningWarning Warning indicates that failure to follow directions could result in bodily harm.

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Where to Get Help If you have questions or comments contact:

Customer Support

Tel 866-EZSTORE (866.397.8673) [email protected]

Document Revision

Date Revision Description 1/6/2009 1 Preliminary 12/16/2008 1.1 Revision 1 1/6/2009 1.2 Revision 2

Common Abbreviations This section contains several of the most commonly abbreviated terms and definitions that are used throughout this document.

• Site Recovery Manager (Abbr. “SRM”) o VMware’s Site Recovery Manger

• Storage Replication Adapter (Abbr. “SRA”)

o The SRA is a component of SRM written by storage array vendors that allows communication between their arrays and SRM.

• Compellent Enterprise Manager (Abbr. “EM”) o Enterprise Manager is administration software that allows for

managing multiple Compellent systems.

• Virtual Infrastructure Client (Abbr. “VI Client”) o A VMware software client that allows connections to Virtual Center or

ESX servers to perform administrative tasks.

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Overview

Prerequisites This document assumes the reader has had formal training or has advanced working knowledge of the following:

• Installation and configuration of VMware Virtual Infrastructure 3 • Configuration and operation of the Compellent Storage Center • Installation and configuration of VMware Site Recovery Manager

Intended audience This document is highly technical and intended for storage and server administrators, as well as other information technology professionals interested in learning more about how VMware Site Recovery Manager integrates with the Compellent Storage Center.

Introduction This document will provide configuration examples, tips, recommended settings, and other storage guidelines a user can follow while integrating VMware Site Recovery Manager with the Compellent Storage Center. This document has been written to answer many frequently asked questions with regard to how VMware interacts with the Site Recovery Manager, as well as basic configuration. Compellent advises customers to read the Getting Started with Site Recovery Manager and the Site Recovery Manager Administration Guide provided on the VMware web site before beginning their SRM implementation. Please note that the information contained within this document is intended only to be general recommendations and may not be applicable to all configurations. There are certain circumstances and environments where the configuration may vary based upon your individual or business needs.

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Setup Prerequisites

Enterprise Manager Compellent Enterprise Manager Version 3.3.x or greater is required for the Storage Replication Adapter (SRA) to function. This is because the SRA makes calls directly to the Enterprise Manager Data Collector to manipulate the storage.

Storage Center It is required to have two Compellent Storage Center (version 4.x or greater) systems with replication between the sites licensed and operational. Site Recovery Manager cannot function without two Compellent systems replicating between one another.

VMware VMware Site Recovery Manager 1.x with the appropriate versions of ESX Server and Virtual Center are needed. Please check the latest Site Recovery Manager Compatibility Matrix for the versions of software required for SRM to function.

Storage Replication Adapter (SRA) The Compellent Storage Replication Adapter is required to be running version 3.3 or greater.

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Site Recovery Manager Architecture

Single Protected Site This configuration is generally used when the secondary site does not have any virtual machines that need to be protected by SRM. In this example (Figure 1), the secondary site functions solely for disaster recovery purposes. Figure 1

In this configuration, the Enterprise Manager Data Collector Server is placed at the disaster recovery site because it is required for SRM to perform recovery functions.



Multiple Protected Sites This configuration is generally used when both sites have virtual machines that need to be protected by SRM. In this example (Figure 2), each site replicates virtual machines to the opposing site in order to protect both sites from a failure. Figure 2

In this configuration, multiple Enterprise Manager Data Collector Servers are placed at each site so that either site can fail.



Enterprise Manager Configuration

Data Collector Configuration As illustrated in the Architecture section, Enterprise Manager is a critical piece to the SRM infrastructure because the data collector processes all the calls from the Storage Replication Adapter (SRA) and relays them to the Storage Centers to perform the work. Deciding whether or not to use one or two Enterprise Manager Servers depends on whether virtual machines need to be protected in one or multiple sites.

• If protecting virtual machines at one site, a single Enterprise Manager Data Collector will suffice, and it is recommended that it be placed at the recovery site.

• If protecting virtual machines at multiple sites, it is recommended to place Enterprise Manager Data Collectors at each site.

Enterprise Manager Logins For SRM to function, the Storage Replication Adapter (SRA) must use Enterprise Manager Login credentials that have rights to both of the Storage Center systems replicating the virtual machine volumes. For example, if Storage Center 910 is replicating virtual machine volumes to Storage Center 911, the login the SRA uses must have access rights to both systems. Figure 3



Configuring Replications When configuring replications for virtual machine volumes, the same credentials that SRA uses to access the Enterprise Manager Data Collector must be used. This is because the SRA relies on the saved restore points attributed to that login to query the replication information.

Saving Restore Points Saving restore points must be completed for the SRA to be able to query the active replications, and can be initiated one of two ways:

1. At the end of the Create Replication Wizard: Figure 4

2. From the Enterprise Manager Options Menu: Figure 5



Validating Restore Points Restore points can be quickly validated from the options menu of Enterprise Manager: Figure 6

Validating the restore points is a good troubleshooting step to determine whether or not a particular replication is visible to the SRA. Figure 7



Automatic Restore Point Saving Schedule The Finish saving Restore Points screen in the Save Restore Points Wizard has the option to save restore points automatically at a selected interval. It is recommended to configure the data collector to save the restore points hourly. This helps to ensure that the most current restore points are available for the SRA to query for replication information. Figure 8

If using multiple Enterprise Manager Data Collectors, the restore points MUST be saved on both data collectors when creating replications before the volume can be protected by SRM.



Site Recovery Manager Configuration

Configuring the Array Managers Configuring the array managers so the Storage Replication Adapter can communicate with the Enterprise Manager Data Collector is performed from the Site Recovery Summary Tab. Figure 9

The Protection Side Array Managers and the Recovery Side Array Managers must both be configured to point to the Enterprise Manager Data Collector that is responsible for their respective sites.

• Single Enterprise Manager Data Collector o The Protection Side Array Manager and the Recovery Side Array

Manager should both specify the data collector at the secondary site. • Multiple Enterprise Manager Data Collectors

o The Protection Side Array Manager should specify the data collector at the primary site, while the Recovery Side Array Manager should specify the data collector at the secondary site.



For example, in a single data collector setup, the Protection Side Array Manager should specify the secondary site data collector and then select the appropriate Storage Center system for that site (see Figure 10 below). Likewise, the Recovery Side Array Manager should specify the same data collector, and then select the other Storage Center system at the secondary site (see Figure 11 below). Figure 10

Figure 11



Rescanning Arrays Whenever a new virtual machine volume is added to the environment, the arrays must be rescanned within SRM in addition to rescanning for new LUNs within the ESX servers. The Rescan Arrays button can be found on the last screen in the array manager’s configuration wizard. Figure 12

By clicking on the Rescan Arrays button on this screen, the SRA will re-query the Enterprise Manager Data Collector to obtain the new replicated virtual machine volume information.

After adding any new volumes to the environment, it is always recommended to Rescan Arrays through this wizard so that SRM can discover the new replications. Just because a LUN is not visible on this screen does not mean that the rescan didn’t take place. The new LUN will usually not be visible on this screen until a protection group is created for it.



Creating Protection Groups Before creating protection groups, it is recommended that an empty VMFS datastore be created at the disaster recovery site to hold the Shadow Virtual Machine configuration files. For each virtual machine protected, SRM will create a “Shadow VM” on the recovery site as a placeholder VM containing the basic configuration files. Although this datastore only needs to be large enough to hold the configuration files for all the recoverable virtual machines, creating a standard sized 300-500 GB datastore should not be thought unreasonable because dynamic capacity will thinly provision the volume. It is likely that only one “Shadow VM” datastore is required because the recovery process will unregister and reregister the recovered virtual machine with the .vmx file on the recovered volume.

Modifying Protection Groups to Exclude Pagefile Volumes For VMware administrators that have separated their Windows pagefiles onto separate datastores, the pagefile volumes can be excluded within SRM so they are not used in the recovery plan. When creating the protection group, virtual disks can be excluded (or even substituted) through the Configure Protection Wizard for each VM. (See Figure 13 below) Figure 13

To exclude the pagefile datastore, simply highlight the virtual disk containing the pagefile.sys, and then select Detach. Assuming there is enough disk space; Windows will automatically recreate a new pagefile on the system drive at boot time.



Creating Recovery Plans When testing or running recovery plans, SRM has no built-in mechanisms to determine whether or not the replication volumes are fully synced before the storage is prepared for the recovery. In other words, there could still be in-flight data actively being replicated to the secondary site that may influence the outcome of the recovery. To help ensure that all data has successfully been replicated to the secondary site, it is recommended that you consider adding Commands and Messages to the recovery plan to help ensure all data has been replicated before the Prepare Storage section is executed. For example, the Compellent CompCU utility could be integrated into a script to take current replays of all the volumes to make sure the most recent data has been replicated. An example script can be found in the appendix of this document. In addition to scripts a Message can be added to the plan which will pause the recovery plan while someone monitors the storage to make sure the replications are synced (see Figure 14 below). Figure 14

When the plan executes, it will not wait for the command script to finish before it moves onto the next step unless there is a Message inserted.



Recovery Plan Execution

Testing a Recovery Plan Testing the recovery plan is non-disruptive to the storage replications and production volumes because the test recoveries use View Volumes created from Replays to run the recovery plan tests. This means that when testing a recovery plan any tests, changes, or updates can be performed on the recovered virtual machines, because they will later be discarded when the test recovery plan cleanup takes place. To test a disaster recovery plan, highlight the recovery plan to be tested and select the Test Recovery Plan button: Figure 15

Running a Recovery Plan When choosing to run a recovery plan, keep in mind this procedure is disruptive and will result in virtual machines being powered off at the primary site, replication mirrors being broken, and virtual machines being recovered at the secondary site. In the event of a disaster, highlight the appropriate recovery plan, and click the Run Recovery Plan button: Figure 16



As a safety precaution the following message (Figure 17) will appear when running a recovery plan. Figure 17

It is important to note that when running a recovery plan the failback to the primary site is a manual procedure. In other words, deciding to fail your virtual machines to the recovery site is a decision that should not be taken lightly due to the work involved reverting back to the primary site.



Failing Back to the Primary Site Although it is a manual process, SRM can be configured to fail virtual machines back to the primary site. Instructions outlining the general steps to accomplish this are located in an appendix in the Enterprise Manager 3.3 User Guide available on Compellent’s Knowledge Center.



Additional Resources

• Compellent Resources o Compellent Home Page

http://www.compellent.com o Compellent Knowledge Center

http://knowledgecenter.compellent.com

• VMware Resources o VMware Home Page

http://www.vmware.com o VMware Knowledge Base

http://kb.vmware.com o VMware Technology Network

http://communities.vmware.com/community/vmtn o VMware Documentation

http://www.vmware.com/support/pubs/

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http://knowledgecenter.compellent.com/�

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http://communities.vmware.com/community/vmtn�

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Appendix A – Example Scripts Script: TakeReplay.cmd Description: This example script uses the Compellent Command Utility to take replays of the source replication system volumes to make sure that the most current replay is replicated to the DR site. "C:\Program Files\Java\jre6\bin\java.exe" ^ -jar c:\scripts\compcu.jar ^ -host 192.168.1.10 ^ -user Admin ^ -password mmm ^ -c "replay create -volume 'Volume_Name_1' -expire 60" "C:\Program Files\Java\jre6\bin\java.exe" ^ -jar c:\scripts\compcu.jar ^ -host 192.168.1.10 ^ -user Admin ^ -password mmm ^ -c "replay create -volume 'Volume_Name_2' -expire 60" This script will connect to a Storage Center with an IP address of “192.168.1.10” with a username of “Admin” and a password of “mmm” to take a replay of “Volume_Name_x” with a replay expiration set to 60 minutes.

The ^ symbols are used in this script for line continuation and readability, but could be excluded if the entire command is placed on one line.

The Compellent Command Utility download, and its associated documentation, can be found in the Compellent Knowledge Center.

Documents

Compellent Best Practices with Site Recovery Manager 1.0