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Sun Cluster Geographic Edition Data Replication Guide for EMC Symmetrix Remote Data Facility

ProcedureHow to Perform a Failback-Switchover on a System That Uses EMC Symmetrix Remote Data Facility Replication

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

Note –

The failback procedures apply only to clusters in a partnership. You need to perform the following procedure only once per partnership.

Before You Begin

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

  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.


      phys-paris-1# geops update partnershipname
      partnershipname

      Specifies the name of the partnership

      Note –

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

      For more information about synchronizing partnerships, see Resynchronizing a Partnership in Sun Cluster Geographic Edition System Administration Guide.

    2. Determine whether the protection group on the original primary cluster, cluster-paris, is active.


      phys-paris-1# geoadm status

    3. If the protection group on the original primary cluster is active, stop it.


      phys-paris-1# geopg stop -e local protectiongroupname

    4. Verify that the protection group is stopped.


      phys-paris-1# geoadm status

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

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


      phys-paris-1# geopg update protectiongroupname
      protectiongroupname

      Specifies the name of the protection group

      For more information about synchronizing protection groups, see Resynchronizing an EMC Symmetrix Remote Data Facility Protection Group.

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

    Ensure that the protection group is not in an error state. A protection group cannot be started when it is in a error state.


    phys-paris-1# geopg validate protectiongroupname
    protectiongroupname

    Specifies a unique name that identifies a single protection group

    For more information, see How to Validate an EMC Symmetrix Remote Data Facility 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.


    phys-paris-1# geopg start -e local protectiongroupname
    -e local

    Specifies the scope of the command.

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

    protectiongroupname

    Specifies the name of the protection group.

    Note –

    Do not use the -n option when performing 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 an EMC Symmetrix Remote Data Facility Protection Group.

  4. Confirm that the data is 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 EMC Symmetrix Remote Data Facility device groups on cluster-newyork have a Synchronized RDF pair state.

    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 both partner clusters, ensure that the protection group is activated.


    # geoadm status

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


    # geopg switchover [-f] -m clusterparis protectiongroupname

    For more information, see How to Switch Over an EMC Symmetrix Remote Data Facility Protection Group From Primary to Secondary.

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

  7. Ensure that the switchover was performed successfully.

    Verify that the protection group is now primary on cluster-paris and secondary on cluster-newyork and that the state for “Data replication” and “Resource groups” is OK on both clusters.


    # geoadm status

    Check the runtime status of the application resource group and data replication for each EMC Symmetrix Remote Data Facility protection group.


    # clresourcegroup status -v protectiongroupname

    Refer to the Status and Status Message fields that are presented for the data replication device group you want to check. For more information about these fields, see Table 2–1.

    For more information about the runtime status of data replication, see Checking the Runtime Status of EMC Symmetrix Remote Data Facility Data Replication.