HP Serviceguard Version A.11.20 Release Notes, August 2011

High Availability Consulting Services
Because Serviceguard configurations can be complex to configure and maintain, HP strongly
recommends that you use its high availability consulting services to ensure a smooth installation
and rollout; contact your HP representative for more information. You should also work with your
HP representative to ensure that you have the latest firmware revisions for disk drives, disk controllers,
LAN controllers, and other hardware.
HP-UX 11i v3 Features Important to Serviceguard
Serviceguard A.11.20 runs only on HP-UX 11i v3, which introduces important improvements over
11i v2, particularly in regard to the I/O subsystem. See the subsections that follow, and “What’s
in this Release” (page 13).
New Bundles
Serviceguard A.11.20 is now available as a recommended product in the HP-UX 11i v3 HA-OE
and DC-OE bundles.
Native Multipathing, Veritas DMP, and Related Features in HP-UX 11i v3
The HP-UX 11i v3 I/O subsystem provides multipathing and load balancing by default. This is
often referred to as native multipathing.
Veritas Volume Manager (VxVM) and Dynamic Multipathing (DMP) from Symantec are supported
on HP-UX 11i v3, but do not provide multipathing and load balancing; DMP acts as a pass-through
driver, allowing multipathing and load balancing to be controlled by the HP-UX I/O subsystem
instead.
When you upgrade a system to HP-UX 11i v3, the I/O subsystem by default will start performing
load balancing and multipathing for all multipath devices (whether or not they are managed by
VxVM/DMP, and whether or not you decide to migrate the system to agile addressing); you do
not have to take any additional steps to make this happen.
For more information about multipathing in HP-UX 11i v3, see the white paper HP-UX 11i v3 Native
Multipathing for Mass Storage, and the Logical Volume Management volume of the HP-UX System
Administrator’s Guide at http://www.hp.com/go/hpux-core-docs. See also “About Device Special
Files (DSFs)” (page 30).
PV Links
Previous editions of Managing Serviceguard recommended creating LVM PV links for LUNs defined
in disk arrays. On HP-UX 11i v3, these PV Links are redundant; they are supported, but will be
inactive unless you turn off native multipathing (in that case they will function as they did in previous
releases of HP-UX).
PCI Error Recovery
PCI Error Recovery enables an HP-UX system to detect, isolate, and automatically recover from a
PCI error. PCI Error Recovery is enabled on HP-UX 11i v3 systems by default, but HP recommends
that it remain enabled in a Serviceguard cluster only if your storage devices are configured with
multiple paths and you have not disabled HP-UX native multipathing.
12 Serviceguard Version A.11.20 Release Notes