Managing Serviceguard 13th Edition, February 2007

Building an HA Cluster Configuration
Creating the Storage Infrastructure and Filesystems with LVM and VxVM
Chapter 5220
Clearimport at System Reboot Time
At system reboot time, the cmcluster RC script does a vxdisk
clearimport on all disks formerly imported by the system, provided
they have the noautoimport flag set, and provided they are not
currently imported by another running node. The clearimport clears
the host ID on the disk group, to allow any node that is connected to the
disk group to import it when the package moves from one node to
another.
Using the clearimport at reboot time allows Serviceguard to clean up
following a node failure, for example, a system crash during a power
failure. Disks that were imported at the time of the failure still have the
node’s ID written on them, and this ID must be cleared before the
rebooting node or any other node can import them with a package control
script.
Note that the clearimport is done for disks previously imported with
noautoimport set on any system that has Serviceguard installed,
whether it is configured in a cluster or not.