HP Serviceguard A.11.20 Release Notes, September 2012

For more information about agile addressing, see following documents at http://www.hp.com/
go/hpux-core-docs:
• the Logical Volume Management volume of the HP-UX System Administrator’s Guide
• the HP-UX 11i v3 Installation and Update Guide
• the following white papers:
The Next Generation Mass Storage Stack◦
◦ HP-UX 11i v3 Native Multi-Pathing for Mass Storage
◦ LVM Migration from Legacy to Agile Naming Model HP-UX 11i v3
See also the HP-UX 11i v3 intro(7) manpage.
Support for HP Integrity Virtual Machines (HPVM)
Serviceguard supports HP Integrity Virtual Machines (HPVM). HPVM runs only on HP Integrity
systems; it does not run on HP 9000 systems.
IMPORTANT: For the most up-to-date compatibility information, see the
Serviceguard/SGeRAC/SMS/Serviceguard Mgr Plug-in Compatibility and Feature Matrix, at
http://www.hp.com/go/hpux-serviceguard-docs —> HP Serviceguard, under the heading
General reference. See also the “Integrity VM/Serviceguard Support Matrix” in the white
paper Designing high-availability solutions with HP Serviceguard and HP Integrity Virtual Machines
on the same web page under White papers.
Serviceguard A.11.20 supports an HPVM either as a package or as a cluster node. If any
Serviceguard cluster node is a virtual machine, the amount of time Serviceguard needs to wait for
a failed node’s I/O to complete increases; see “About HPVM and Cluster Re-formation Time”
(page 33).
See also “About cmappmgr” (page 31).
About HPVM and Cluster Re-formation Time
When 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.
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.
The additional time Serviceguard needs to wait depends in part on whether or not a VM guest
depot is installed on the VM node. (See the HP-UX vPars and Integrity VM V6.1 Administrator
Guide at the address given below, for information on installing a guest depot.) Serviceguard uses
information it derives from the VM guest depot to set the timeout to the optimal value. If any VM
node does not have a VM guest depot, 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.
Features Introduced Before A.11.20 33