14.7 Mirroring an Existing Pool with NSSMU

  1. Before you begin, review the Section 14.2.2, Guidelines for Software RAID 1 Devices.

  2. In NSSMU, select Partitions from the NSSMU main menu.

  3. From the list of existing partitions, select the NSS partition for the pool you want to mirror.

  4. Press F3 to create the RAID 1 device and mirror the partition where the pool resides.

  5. From the available devices, select up to three additional devices that you want to use as a segment, then press Enter.

    On the page where you select the second partition, you have to press the space bar to select the partition for the second mirror. When it is truly selected, the asterisk next to it stays there even if you move up and down in the list. Then press F3 to mirror. The message pops up to confirm creating the mirror.

    The space assigned is the same size as the existing partition. The segments must reside on different devices. If no partitions appear, it is an indication that either there are no partitions large enough or no free space exists on other devices.

  6. To confirm the RAID 1 device, select RAID Devices from the NSSMU Main menu. The RAID 1 device ID appears in the RAID Devices window.

  7. Select the RAID device, then view its details to make sure that synchronization has begun.

    The remirroring status shows a percentage is greater than 0. It is fully synchronized at 100%If you are mirroring a shared partition (that is, if it contains a cluster-enabled pool), the synchronization to the mirror does not begin automatically. Continue with Step 8.a.

  8. If you are mirroring a shared partition (that is, if it contains a cluster-enabled pool), start the remirroring manually by doing the following:

    1. Use one of the following methods to initiate mirroring for the newly created mirror:

      • At the server console of a cluster node, enter the following to migrate the cluster resource to another node:

        cluster migrate cluster_resource destination_node_name

        Migrating the pool causes load scripts to be executed and causes the mirroring to start on the new node.

      • At the server console of the cluster node where the pool is currently active, enter

        dmsetup message raid_device_name 0 remirror=on

        WARNING:Issue this command only on the node where the pool is currently active. Issuing the command on multiple nodes can corrupt the mirror.

    2. Verify that the remirroring has begun by opening NSSMU on the node where the pool is currently active, open the RAID page, then select the RAID device.

      The remirroring status shows a percentage is greater than 0. It is fully synchronized at 100%.