Recovery Using SQL Server Database Mirroring: Moving CommCell Operations to the Standby CommServe Host
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.
High-Level Process Flow
The process flow for moving the CommCell operations to the standby CommServe host involves the following tasks in the order listed:
- 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 (WFEngine, DM2, or cvCloud) on the standby CommServe host.
Refer to the Microsoft manual for instructions on running these SQL commands.
- Update the CommServe database with the hostname of the standby CommServe host. See Restoring CommCell Operations on the CommServe Host for instructions on changing the CommServe host name.
- Make sure the software updates are installed on the standby CommServe host. See Applying Updates on the Standby CommServe Host.
- Start the CommCell services on the standby CommServe Host. See Starting a Service.
- Update the CommServe name for all Clients and MediaAgents. See Updating the CommServe Name for Clients and MediaAgents.
- 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.