Starting the Mirror

You can start mirroring through MCS and using the CLI.

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.

Starting the Mirror for Multiple Mirror Volumes Using the MapR Control System

To start mirroring, in the Summary tab under Data > Volumes:

  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 dropdown 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 MapR Control System

To start mirroring:

  1. Go to the volume information page for the mirror volume to synchronize.
  2. Select Start Mirroring from the Select Action dropdown 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

The basic command to start a mirror is:

maprcli volume mirror start -name <volume name>

For complete reference information, see volume mirror start.