HP Serviceguard A.11.20 Release Notes, September 2012

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 32).
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.
IMPORTANT: If your storage devices are configured with only a single path, or you have disabled
multipathing, you should disable PCI Error Recovery; otherwise Serviceguard may not detect when
connectivity is lost and cause a failover.
For instructions on using the pci_eh_enable parameter to disable PCI Error Recovery, see the
“Tunable Kernel Parameters” section of the latest edition of the PCI Error Recovery Product Note
which you can find at http://www.hp.com/go/hpux-networking-docs —> HP-UX 11i v3
Networking Software.
Online Replacement of LAN Cards Requires Patch
Before you can replace a LAN card online (without bringing down the cluster) as described under
“Replacing LAN or Fibre Channel Cards” in Chapter 8 of Managing Serviceguard, you must apply
patch PHNE_35894 or a later cumulative patch. If you have installed HP-UX 11i v3 0703 Fusion
release and later, you need not install this patch as it has been merged into the OE. See “Patches
for this Version” (page 48) and “QXCR1000575890: OLR of a LAN Card in SG cluster fails on
HP-UX 11i v3” (page 48).
For more information about replacing interface cards online, see the Interface Card OL* Support
Guide for HP-UX 11i v3, at http://www.hp.com/go/hpux-core-docs -> HP-UX 11i v3 ->
User guide.
What’s in this Release
This release of Serviceguard A.11.20 runs only on 11i v3 (see “Serviceguard on HP-UX 11i v3”
(page 14)) and adds new functionality.
12 Serviceguard Version A.11.20 Release Notes