If a disk unit in a mirrored pair fails, you need to suspend mirroring to repair or replace it. If you want to suspend mirroring on an independent disk pool that is unavailable, you can do so when your system is fully restarted. For all other disk pools, you need to restart your system to the dedicated service tools (DST) mode before suspending mirroring.
Mirrored protection is local to a single server and is distinct from cross-site mirroring or geographic mirroring.