I had a server deactivate an NSS volume the other day. Rebooted the server
and it came back normally.

The message I found after it came back up was this.
Severity = 4 Locus = 3 Class = 0

NSS-3.00-5002: Pool SERVER1/VOL1 is being deactivated.

An error (20444(beastTree.c[3097])) at block 0(file block 0)(ZID 0) has
compromised volume integrity.

NSS verify or rebuild in order? I have not seen this error before. It's
about a 2TB Pool.