How to Perform a Failback-Switchover on a System That Uses Hitachi TrueCopy Replication

Use this procedure to restart an application on the original primary cluster, cluster-paris, after this cluster's data has been resynchronized with the data on the current primary cluster, cluster-newyork.

Before You Begin

Before you perform a failback-switchover, a takeover has occurred on cluster-newyork. The clusters now have the following roles:

• If the original primary cluster, cluster-paris, has been down, confirm that the cluster is booted and that the Sun Cluster Geographic Edition infrastructure is enabled on the cluster. For more information about booting a cluster, see Booting a Cluster.

• The protection group on cluster-newyork has the primary role.

• The protection group on cluster-paris has either the primary role or secondary role, depending on whether the protection group could be reached during the takeover.

Steps

1. Resynchronize the original primary cluster, cluster-paris, with the current primary cluster, cluster-newyork.

   cluster-paris forfeits its own configuration and replicates the cluster-newyork configuration locally. Resynchronize both the partnership and protection group configurations.

   1. On cluster-paris, resynchronize the partnership.

      # geops update partnership-name

      partnership-name

      Specifies the name of the partnership

      ---

      Note –

      You need to perform this step only once, even if you are performing a failback-switchover for multiple protection groups.

      ---

      For more information about synchronizing partnerships, see Resynchronizing a Partnership.

   2. On cluster-paris, resynchronize each protection group.

      Because the role of the protection group on cluster-newyork is primary, this steps ensures that the role of the protection group on cluster-paris is secondary.

      # geopg update protection-group-name

      protection-group-name

      Specifies the name of the protection group

      For more information about synchronizing protection groups, see Resynchronizing a Hitachi TrueCopy Protection Group.

2. On cluster-paris, validate the cluster's configuration for each protection group.

   # geopg validate protection-group-name

   protection-group-name

   Specifies a unique name that identifies a single protection group

   For more information, see How to Validate a Hitachi TrueCopy Protection Group.

3. On cluster-paris, activate each protection group.

   Because the protection group on cluster-paris has a role of secondary, the geopg start command does not restart the application on cluster-paris.

   # geopg start -e local protection-group-name

   -e local

   Specifies the scope of the command

   By specifying a local scope, the command operates on the local cluster only.

   protection-group-name

   Specifies the name of the protection group

   ---

   Note –

   The -n option must not be given when doing a failback-switchover because the data needs to be synchronized from the current primary, cluster-newyork, to the current secondary, cluster-paris.

   ---

   Because the protection group has a role of secondary, the data is synchronized from the current primary, cluster-newyork, to the current secondary, cluster-paris.

   For more information about the geopg start command, see How to Activate a Hitachi TrueCopy Protection Group.

4. Before performing the switchover, wait for the data to be completely synchronized.

   The data is completely synchronized when the state of the protection group on cluster-newyork is OK. The protection group has a local state of OK when the Hitachi TrueCopy device groups on cluster-newyork have a state of PVOL_PAIR and the Hitachi TrueCopy device groups on cluster-paris have a state of SVOL_PAIR.

   To confirm that the state of the protection group on cluster-newyork is OK use the following command:

   phys-newyork-1# geoadm status

   Refer to the Protection Group section of the output

5. On either cluster, perform a switchover from cluster-newyork to cluster-paris for each protection group.

   # geopg switchover [-f] -m cluster-paris protection-group-name

   For more information, see How to Switch Over a Hitachi TrueCopy Protection Group From Primary to Secondary.

   cluster-paris resumes its original role as primary cluster for the protection group.