HP Serviceguard Version A.11.17 on HP-UX 11i v3 Release Notes, February 2007

Serviceguard Version A.11.17 on HP-UX 11i v3 Release Notes
Announcements
Chapter 1 9
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 in the HP-UX 11i v3 Operating Environments
collection at http://docs.hp.com. See also “About Device Special Files
(DSFs)” on page 13.
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 in the High
Availability collection on docs.hp.com.