Starting the Mirror

Explains how to start a mirror operation using either the Control System or the CLI.

About this task

When a mirror starts, all the data in the source volume is copied into the mirror volume. Starting a mirroring operation requires the mirror volume to exist and be associated with a source. After you start a mirror, synchronize it with the source volume regularly to keep the mirror current.

NOTE
The getIPTypeForCluster method in CLDBRpcCommonUtils is unable to determine whether the IP type is internal or external, if mapr-clusters.conf contains both internal and external IPs. The fix is to only put in the internal IP in mapr-clusters.conf and keep the external IP in the env.sh file, before starting the mirror.

Starting the Mirror for Multiple Mirror Volumes Using the Control System

About this task

To start mirroring, in the Summary tab under Data > Volumes:
NOTE
The Summary tab is under the Volumes tab in the Kubernetes version of the Control System.

Procedure

  1. Select the mirror volume(s) to synchronize.
    You cannot start mirror for:
    • Standard volumes
    • Mirror volumes currently mirroring
  2. Select Start Mirroring from the Actions drop-down menu.
    The Start Mirroring Volume(s) confirmation dialog displays.
  3. Verify the list of volumes to synchronize and click Start Mirroring.
    When a mirror is started, the mirror volume is synchronized from a hidden internal snapshot so that the mirroring process is not affected by any concurrent changes to the source volume. The changes to the mirror volume occur atomically at the end of the mirroring process; deltas transmitted from the source volume do not appear until mirroring is complete.

Starting the Mirror for a Mirror Volume Using the Control System

About this task

To start mirroring:

Procedure

  1. Go to the volume information page for the mirror volume to synchronize.
  2. Select Start Mirroring from the Select Action drop-down menu.
    The Start Mirroring Volume confirmation dialog displays.
  3. Click Start Mirroring.
    When a mirror is started, the mirror volume is synchronized from a hidden internal snapshot so that the mirroring process is not affected by any concurrent changes to the source volume. The changes to the mirror volume occur atomically at the end of the mirroring process; deltas transmitted from the source volume do not appear until mirroring is complete.

Starting the Mirror Using the CLI or REST API

About this task

The basic command to start a mirror is:

maprcli volume mirror start -name <volume name>

For complete reference information, see volume mirror start.