Chapter 3. Configure Disaster Recovery using Geo-replication

Geo-replication is used to synchronize data from one Red Hat Gluster Storage cluster to another. Synchronizing the local data volume from your discrete Red Hat Hyperconverged Infrastructure (RHHI) cluster to a central data center on a regular basis helps ensure you can restore your cluster to a working state after an outage.

Important

When used in conjunction with Red Hat Hyperconverged Infrastructure, geo-replication for disaster recovery is supported only as a method of backing up data. Failover (promoting a slave volume) and failback (syncing to a restored master volume) are not supported for the Red Hat Hyperconverged Infrastructure use case.

3.1. Configuring geo-replication for disaster recovery

3.1.1. Before you begin

  • Prepare a remote backup volume to hold the geo-replicated copy of your local volume.

    • Ensure that the local volume you want to back up has shared storage enabled. Run the following command on the master node to enable shared storage:

      # gluster volume set all cluster.enable-shared-storage enable
    • Ensure that your remote backup volume has sharding enabled. Enable sharding by running the following command on any of the nodes that host the remote backup volume:

      # gluster volume set VOLNAME features.shard enable

3.1.2. Configuring a geo-replication session

  1. Create (but do not start) the geo-replication session

    From any master node, create (but do not start) a geo-replication session from a local volume to the remote backup volume.

    See the Red Hat Gluster Storage 3.3 Administration Guide for details: https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.3/html/administration_guide/sect-Preparing_to_Deploy_Geo-replication#Setting_Up_the_Environment_for_Geo-replication_Session

3.1.3. Configuring synchronization schedule

  1. Verify that geo-replication is configured

    In Red Hat Virtualization Manager for the master node, click the Volumes tab.

    Check the Info column for the geo-replication icon. If present, a geo-replication session is configured for that volume.

  2. In the Storage Domain tab, select the storage domain to back up.
  3. Click the Remote Data Sync Setup sub-tab

    The Setup Remote Data Synchronization window opens.

    1. In the Geo-replicated to field, select the backup destination.
    2. In the Recurrence field, select a recurrence interval type.

      Valid values are WEEKLY with at least one weekday checkbox selected, or DAILY.

    3. In the Hours and Minutes field, specify the time to start synchronizing.

      Note

      This time is based on the Hosted Engine’s timezone.

    4. Click OK.
  4. Check the Events pane at the time you specified to verify that synchronization works correctly.

3.1.4. Deleting synchronization schedule

  1. In the Storage Domain tab, select the storage domain to back up.
  2. Click the Remote Data Sync Setup sub-tab

    The Setup Remote Data Synchronization window opens.

    1. In the Recurrence field, select a recurrence interval type of NONE.
    2. Click OK.
  3. (Optional) Remove the geo-replication session

    Run the following command from the geo-replication master node:

    # gluster volume geo-replication MASTER_VOL SLAVE_HOST::SLAVE_VOL delete

    You can also run this command with the reset-sync-time parameter. For further information about this parameter and geo-replication in general, see the Red Hat Gluster Storage Administration Guide: https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.3/html/administration_guide/chap-managing_geo-replication.