This is a follow up tutorial on the DRBD replication posts about promoting the DR site as the main site when PR is failed.
More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk replication of a production cluster to a remote cluster on RHEL6
In some situations we have to promote the DR site as the main site without performing a nice site switch as described in DRBD: Gracious role switching of live sites configured with DRBD replication
The situations when this must be performed are:
1. The live site experienced a total failure.
2. The live site is completely isolated from the participants due to a communication failure
Note that in both cases the PR site is considered as failed.
The following steps must be performed:
1. Ensure that the conditions from the above paragraph are met.
2. Stop the DRBD_Slave_Service on the standby site
#clusvcadm -s DRBD_Slave_Service
3. Start the Database_Service on the standby site
#clusvcadm -e Database_Service -F
4. Start the Application_Service on the standby site
#clusvcadm -e Applications_Service -F
Instruct the enterprise clients to switch operations to the DR site as the main site.