HP Serviceguard for Linux Version A.11.18 Release Notes, 2nd Edition, March 2009

NOTE: If you use the cmmigratepkg utility to convert a package that includes
the SGLX_VM parameter, you will see a warning; for more information see
“JAGag48881 (SR8606496963): cmmigrate does not handle virtual machine package
script updates ” (page 79).
• Serviceguard running on VMware virtual machines requires the sg_persist
command, which you may need to install separately, depending on your platform
and Linux distribution. See Using Serviceguard for Linux with VMware Virtual
Machines at the address given under “For More Information” (page 36).
About Virtual Machines and Cluster Re-formation Time
General case
Whenever a node fails and the cluster re-forms, Serviceguard must wait a certain
amount of time to allow I/O from the failed node to be written out to the target storage
device. Only after that time has elapsed can Serviceguard allow an adoptive node access
to that device; otherwise data corruption could occur. The amount of time Serviceguard
waits is calculated by Serviceguard and is not user-configurable.
Additional time needed for Virtual Machine nodes
The above is true whether or not the cluster includes virtual machines (VMs), but using
VMs as Serviceguard nodes increases the amount of time Serviceguard needs to wait
before it is safe to allow another node access to the same storage. This additional wait
can increase cluster re-formation time by as much as 70 seconds.
Additional timeout calculation and hpvminfo or vminfo
How much additional time Serviceguard needs to wait depends in part on whether or
not you have installed HP software including the hpvminfo or vminfo command on
the VM node. For installation information, see “For More Information” (page 36).
NOTE: hpvminfo and related software for HP Integrity systems are entirely different
from vminfo for VMware ESX Server and related software for x86 and x86-64 systems.
You cannot run the software for HP Integrity on an x86 or x86-64 system; and vice versa.
Serviceguard uses information it derives fromvminfo or hpvminfo to set the timeout
to the optimal value. If any VM node does not have thevminfo or hpvminfo software,
Serviceguard may not be able to obtain the information it needs to set the optimal
timeout, and in that case it sets the additional timeout to the maximum value, 70 seconds.
What’s in this Release 35