Rejoining the mirrored aggregates to reestablish a MetroCluster configuration

You must rejoin the mirrored aggregates if the mirrored aggregate was in a normal state before the forced takeover.

If you attempt a giveback operation prior to rejoining the aggregates, you might cause the node to boot with a previously failed plex, resulting in a data service outage.
  1. Validate that you can access the remote storage by entering the following command: aggr status -r
  2. Turn on power to the node at the disaster site. After the node at the disaster site boots, it displays the following message: Waiting for Giveback...
  3. Determine which aggregates are at the surviving site and which aggregates are at the disaster site by entering the following command: aggr status Aggregates at the disaster site show plexes that are in a failed state with an out-of-date status. Aggregates at the surviving site show plexes as online.
  4. If aggregates at the disaster site are online, take them offline by entering the following command for each online aggregate: aggr offline disaster_aggr

    disaster_aggr is the name of the aggregate at the disaster site.

    Note: An error message appears if the aggregate is already offline.
  5. Re-create the mirrored aggregates by entering the following command for each aggregate that was split: aggr mirror aggr_name -v disaster_aggr

    aggr_name is the aggregate on the surviving site’s node.

    disaster_aggr is the aggregate on the disaster site’s node.

    The aggr_name aggregate rejoins the disaster_aggr aggregate to reestablish the MetroCluster configuration.
  6. Verify that the mirrored aggregates have been re-created by entering the following command: aggr status -r The giveback operation only succeeds if the aggregates have been rejoined.
  7. Enter the following command at the partner node: cf giveback The node at the disaster site reboots.

Example of rejoining aggregates

The following example shows the commands and status output when you rejoin aggregates to reestablish the MetroCluster configuration.

First, the aggregate status of the disaster site’s storage is shown, in this case after access to the partner node at the surviving site is reestablished:

filer1> aggr status -r
Aggregate mir (online, normal) (zoned checksums)
  Plex /mir/plex5 (online, normal, active)
    RAID group /filer1/plex5/rg0 (normal)

RAID Disk Device HA  SHELF BAY CHAN  Used (MB/blks) Phys (MB/blks)
--------- ------ ------------- ----- -------------- -------------
parity   8a.2   8a   0     2   FC:B  34500/70656000 35003/71687368
data     8a.8   8a   1     0   FC:B  34500/70656000 35003/71687368

Aggregate mir(1) (failed, out-of-date) (zoned checksums)
  Plex /mir(1)/plex1 (offline, normal, out-of-date)
    RAID group /mir(1)/plex1/rg0 (normal)

RAID Disk Device HA  SHELF BAY CHAN  Used (MB/blks) Phys (MB/blks)
--------- ------ ------------- ----- -------------- -------------
parity   6a.0   6a   0     0   FC:B  34500/70656000 35003/71687368
data     6a.1   6a   0     1   FC:B  34500/70656000 35003/71687368

  Plex /mir(1)/plex5 (offline, failed, out-of-date)

Next, the mirror is reestablished using the aggr mirror -v command.

Note: The node at the surviving site is called filer1; the node at the disaster site is called filer2.
filer1> aggr mirror mir -v mir(1)
This will destroy the contents of mir(1).  Are you sure? y
Mon Nov 18 15:36:59 GMT [filer1: raid.mirror.resync.snapcrtok:info]: mir: created mirror resynchronization snapshot mirror_resync.1118153658(filer2)
Mon Nov 18 15:36:59 GMT [filer1: raid.rg.resync.start:notice]: /mir/plex6/rg0: start resynchronization (level 1)
Mon Nov 18 15:36:59 GMT [filer1: raid.mirror.resync.start:notice]: /mir: start resynchronize to target /mir/plex6

After the aggregates rejoin, the synchronous mirrors of the MetroCluster configuration are reestablished:

filer1> aggr status -r mir
Aggregate mir (online, mirrored) (zoned checksums)
  Plex /mir/plex5 (online, normal, active)
    RAID group /mir/plex5/rg0 (normal)

RAID Disk Device HA  SHELF BAY CHAN  Used (MB/blks) Phys (MB/blks)
--------- ------ ------------- ----- -------------- -------------
parity   8a.2   8a   0     2   FC:B  34500/70656000 35003/71687368
data     8a.8   8a   1     0   FC:B  34500/70656000 35003/71687368

  Plex /mir/plex6 (online, normal, active)
    RAID group /mir/plex6/rg0 (normal)

RAID Disk Device HA  SHELF BAY CHAN  Used (MB/blks) Phys (MB/blks)
--------- ------ ------------- ----- -------------- -------------
parity   6a.0   6a   0     0   FC:B  34500/70656000 35003/71687368
data     6a.1   6a   0     1   FC:B  34500/70656000 35003/71687368