Attempting a NDU from 8.3.1 to 9.1 and in the validation phase the subject error is reported.
volume show -state !online -state !restricted reports 1 volume with a name of vol0 on my second node.
I found this KB: Volumes were found that must be changed to online state before attempting NDU - NetApp Knowledge Base
But it just states to contact support. Does anyone know how to correct this error? Our support ran out and I don't know how long it's going to take for it to be reinstated after the purchase has been approved.