VERITAS Volume Manager 4.1 Administrator's Guide

Administering Cluster Functionality

Cluster Initialization and Conﬁguration

Chapter 10366

successful shutdown can require a lot of time (minutes to hours). For

instance, many applications have the concept of draining, where they

accept no new work, but complete any work in 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. 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.

NOTE The MC/ServiceGuard cmhaltnode command ﬁrst attempts to halt all

packages that are using shared disks before attempting to shut down

VxVM. If an application running outside of a deﬁned package performs

I/O to a shared volume, it can delay shutdown of VxVM, resulting in an

MC/ServiceGuard timeout.