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Recovery Using SQL Server Database Mirroring: Moving CommCell Operations to the Standby CommServe Host

Caution

SQL database mirroring is deprecated by Microsoft and may not be available in future versions of Microsoft SQL Server. Therefore, we recommend that you build the CommServe Disaster Recovery Using CommServe LiveSync For High Availability Disaster Recovery.

You may switch CommCell operations from the production CommServe host to the standby CommServe host in the following scenarios:

  • The production CommServe host fails due to a disaster. In this situation the production CommServe is inactive and can not establish network connection with standby CommServe. You must force services to failover to standby CommServe.

  • The production CommServe becomes unavailable because of scheduled software or hardware maintenance. In this scenario, you can initiate the manual failover if the primary CommServe is active.

Procedure

  1. Bring the CommServe database to a consistent state by using the following SQL query on the standby CommServe host. Refer to the Microsoft manual for instructions on running SQL queries in SQL Management Studio. 

    ALTER DATABASE CommServ SET PARTNER FORCE_SERVICE_ALLOW_DATA_LOSS

    Similarly, if mirroring is configured, bring online the other CommCell databases (HistoryDB, WFEngine, DM2, or cvCloud) on the standby CommServe host.

    Refer to the Microsoft manual for instructions on running these SQL commands.

  2. Update the CommServe database with the hostname of the standby CommServe host using the CSRecoveryAssistant.exe. See Recovery Using the Recovery Assistant Tool for step-by-step instructions.

  3. Make sure the software updates are installed on the standby CommServe host. See Installing Service Packs.

  4. Start the CommCell services on the standby CommServe Host. See Starting a Service.

  5. Using DNS, configure the host name of the production CommServe computer to point to the IP address of the standby computer.

    If you do not use DNS, contact customer support for assistance.

    Important

    Verify that all client computers point to the host name of the CommServe computer, and not to the IP address. For instructions on changing the CommServe name on clients, see Changing the Client Computer Name.

  6. Perform frequent disaster recovery backups on the standby CommServe host. See Performing a disaster recovery backup.

If there are inconsistencies between the DDB and the CommServe database during a backup or auxiliary copy operation, the DDBs are put in maintenance mode and an appropriate event message is displayed in the Event Viewer window. In such cases, run DDB Resynchronization to bring the DDBs online and revert it to a reusable state from the maintenance mode. See Resynchronizing the Deduplication Database.

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