Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

■ If all volumes in shared disk groups are closed, VxVM makes them unavailable
to applications. Because all nodes are informed that these volumes are closed
on the leaving node, no resynchronization is performed.
■ If any volume in a shared disk group is open, the shutdown operation in the
kernel waits until the volume is closed. There is no timeout checking in this
operation.
Once shutdown succeeds, the node has left the cluster. It is not possible to access
the shared volumes until the node joins the cluster again.
Since shutdown can be a lengthy process, other reconfiguration can take place
while shutdown is in progress. Normally, the shutdown attempt is suspended
until the other reconfiguration completes. However, if it is already too far
advanced, the shutdown may complete first.
Node abort
If a node does not leave a cluster cleanly, this is because it crashed or because
some cluster component made the node leave on an emergency basis. The ensuing
cluster reconfiguration calls the VxVM abort function. This procedure immediately
attempts to halt all access to shared volumes, although it does wait until pending
I/O from or to the disk completes.
I/O operations that have not yet been started are failed, and the shared volumes
are removed. Applications that were accessing the shared volumes therefore fail
with errors.
After a node abort or crash, shared volumes must be recovered, either by a
surviving node or by a subsequent cluster restart, because it is very likely that
there are unsynchronized mirrors.
Cluster shutdown
If all nodes leave a cluster, shared volumes must be recovered when the cluster
is next started if the last node did not leave cleanly, or if resynchronization from
previous nodes leaving uncleanly is incomplete. CVM automatically handles the
recovery and resynchronization tasks when a node joins the cluster.
Upgrading cluster functionality
The rolling upgrade feature allows you to upgrade the version of VxVM running
in a cluster without shutting down the entire cluster. To install the new version
of VxVM running on a cluster, make one node leave the cluster, upgrade it, and
471Administering cluster functionality
Upgrading cluster functionality