QR Disaster Recovery Solution for Building a Windows Standby SQL Server

Overview

Configuration

• Prepare the Production Server
• Prepare the Standby Server
• Configure the Quick Recovery Agent

Bring the Standby Server online

Overview

This document describes the procedure to create a Standby SQL Server in the event that a Production SQL Server is temporarily or permanently unavailable.

These procedures are supported for SQL Server, on either a Windows 2000 or Windows 2003 machine. It has been certified with the Quick Recovery Agent and QSnap, using the QSnap snap engine for Windows 2000, and the VSS snap engine for Windows 2003. A familiarity with the functionality and configuration of the Quick Recovery Agent is necessary in order to properly conduct this procedure.

In the configuration stage, you will prepare the Production and Standby Servers for the procedure. The Quick Recovery Agent will copy the data from the Production Server to the Standby Server. To use the Standby Server, you will attach the database(s) that have been protected. SQL functionality will then continue using the Standby Server.

The document contains four sections. First, the Production Server is configured. Second, the Standby Server is configured. Third, the Quick Recovery Volumes that will be used on the Standby Server are created. Fourth, the application is brought online.

Advantages

• Very fast recovery time. Recovery time is limited to the time taken to attach the SQL databases.
• Recovery time does not include a lengthy restore from tape or other media.
• There is no need to restore the system state, reinstall SQL, or its Service Packs.

Configuration

The following sections discuss preparing the Production and Standby Servers as well as configuring the QR Agent. The basic workflow is described below. For detailed instructions on installation and configuration options, see Quick Recovery Agent.

Prepare the Production Server

This procedure assumes that the Production Server has already been installed with SQL Server with the latest service packs or patches that may be needed.

1. Record your SQL configuration and storage locations so that SQL can be installed identically on the Standby Server.
2. Install the Quick Recovery Agent and QSnap on the Production Server. If you want to use VSS as your snap engine, install the VSS Enabler in addition to the other products already mentioned. If necessary, install the CommCell Console as a Stand-Alone Application.

Prepare the Standby Server

Before installing any software on the Standby Server, verify the following:

• The Standby Server has adequate resources to host the SQL database(s).
• The QR volumes that will be created on the Standby Server must be equal to or greater than the size of the Primary volumes on the Production Server.

1. Install SQL Server and apply any service packs or patches. The location of the install should be the same as the Production Server.
2. Set up the SQL Server with the same instance names and configuration as the Production Server.
3. Install the Quick Recovery Agent, QSnap, and MediaAgent on the Standby Server. If necessary, install CommCell Console as a Stand-Alone Application.

Configure the Quick Recovery Agent

1. Configure the scratch volume pool. The scratch volume pool for this recovery scenario should consist of the disk resources attached to the Standby Server. The QR volumes and incremental updates will be written to these volumes. For more information, see Scratch Volume Pools.
2. Create a QR Policy. Select the LAN Copy Manager (LANVolCopy) on the Standby Server as the copy manager, and associate this QR Policy with the scratch volume pool that was created in the previous step.
3. Create the QR Agent subclient(s) on the Production Server. Please note the following:
   • The QR Agent manages SQL databases on the database level. Therefore, all the volumes associated with a given database (mdf, ndf, ldf) should be selected as subclient content.
   • Adding volumes that contain SQL data to a QR subclient is accomplished through the Add App button located in the Subclient Content property box.
4. Start or schedule the QR incremental update job.
   1. From the QR Volume Creation Advanced Options dialog box, assign each volume on the Production Server to its corresponding destination volume on the Standby Server.
   2. Set the mount path of each production volume to the drive letter of the corresponding volume on the Standby Server.

The frequency of the incremental updates determines how often new and changed blocks are copied to the QR volumes. The database will be recovered to its state at the time of the last incremental update.

Bring the Standby Server online

In cases where the Production Server suffers a failure, or requires downtime, the Standby Server can quickly be brought on-line to host the database(s) from the QR Volumes you have created.       

Standby Server – Different Name from the Production Server

1. If necessary, reassociate all SQL scripts to the new machine name.
2. Start the SQL Services on the Standby Server.
3. Using SQL Enterprise Manager, attach the database(s) to the appropriate Instance. At this time, the database(s) will be online, and available to use.

Standby Server – Same Name as the Production Server

1. Remove the name of the source machine from Active Directory. This can be done by either renaming the source machine, or shutting it down and manually deleting the entry from Active Directory Users and Computers.
2. Rename the Standby Server to match the name of the Production Server that has been removed from Active Directory. If the machine name is still in Active Directory, allow time for Active Directory to Replicate throughout the domain.
3. Reboot the Standby Server; for the new machine name to take effect.
4. Start the SQL services on the Standby Server.
5. Using SQL Enterprise Manager, attach the database(s) to the appropriate instance. At this time, the database(s) will be online, and available to use.

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