Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

402 Administering cluster functionality
Cluster initialization and configuration
progress before exiting. This process can take a long time if, for example, a long-running
transaction is active.
When the VxVM shutdown procedure is invoked, it checks all volumes in all shared disk
groups on the node that is being shut down. The procedure then either continues with the
shutdown, or fails for one of the following reasons:
■ 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.
Note: Once shutdown succeeds, the node has left the cluster. The node cannot access the
shared volumes until it 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.