Solaris Volume Manager Administration Guide

Handling State Database Replica Errors

How does Solaris Volume Manager handle failed replicas?

The system will continue to run with at least half of the available replicas. The system will panic when fewer than half of the replicas are available.

The system can reboot multiuser when at least one more than half of the replicas are available. If fewer than a majority of replicas are available, you must reboot into single-user mode and delete the unavailable replicas (by using the metadb command).

For example, assume you have four replicas. The system will stay running as long as two replicas (half the total number) are available. However, to reboot the system, three replicas (half the total plus one) must be available.

In a two-disk configuration, you should always create at least two replicas on each disk. For example, assume you have a configuration with two disks, and you only create three replicas (two replicas on the first disk and one replica on the second disk). If the disk with two replicas fails, the system will panic because the remaining disk only has one replica and this is less than half the total number of replicas.

Note –

If you create two replicas on each disk in a two-disk configuration, Solaris Volume Manager will still function if one disk fails. But because you must have one more than half of the total replicas available for the system to reboot, you will be unable to reboot.

What happens if a slice that contains a state database replica fails?

The rest of your configuration should remain in operation. Solaris Volume Manager finds a valid state database during boot (as long as there are at least half plus one valid state database replicas).

What happens when state database replicas are repaired?

When you manually repair or enable state database replicas, Solaris Volume Manager updates them with valid data.