Performing failover on a mirror

Replication and Disaster Recovery Administration Guide for Hitachi NAS Platform

Version
15.1.x
Audience
anonymous
Part Number
MK-92HNAS009-29

Failing over is useful as a test procedure or in order to minimize disruption while production storage is under maintenance. This procedure does not apply to GAD. GAD failover is invisible to the NAS server.

CAUTION:
Failover always involves a brief loss of service.
To fail over a mirror
  1. Unmount all file systems on the span you want to fail over.
  2. Use your storage management interface to ensure that the S-Vols contain an up-to-date copy of the data on the P-Vols. If relationships are synchronous, this means ensuring that the relationships are healthy; otherwise, it can mean running an update command or script.
  3. Use your storage management interface to promote the current S-Vols to the primary role and demote the current P-Vols to the secondary role.
  4. Run the pn all span-list command until it shows that the span is healthy again throughout the cluster.
  5. Remount the filesystems. To fail back, repeat the procedure.