HP Serviceguard Storage Management Suite Version A.02.00 for HP-UX 11i v3 Release Notes, 3rd Edition, November 2008

Dirty Region Logging (DRL) for Mirrored Volumes
If a system failure occurs while mirrored volumes are in use, the mirrors will recover and clean
up any writes that were in progress when the system failed. The Dirty Region Logging (DRL)
feature tracks writes that are in progress to reduce the recovery effort after a system failure.
Without DRL, the entire volume must be recovered, because there is no way to determine which
blocks had writes in progress at the time of the system failure.
The recovery operation is I/O intensive and can be time consuming, depending on the number
of volumes and how large they are. In a clustered environment the IO performance of multiple
nodes using the same volume will be impacted during recovery.
HP strongly recommends that you use DRL with mirrored data volumes in a clustered
environment to enable faster volume recovery. However, Oracle database volumes should be
configured without DRL, because the Oracle database application keeps its own logs and does
not require VxVM to maintain logs. For information on DRL and the Veritas™ SmartSync Recovery
Accelerator, see the Veritas™ Volume Manager Administrator’s Guide, HP-UX 11i v3, 5.0.
HP-UX Operating Environment Upgrade Limitations
When you purchase an HP Serviceguard Storage Management Suite (SG SMS) Operating
Environment (OE) bundle, the SG SMS software is provided on one DVD and the HP-UX OE
(Mission Critical - MCOE, Data Center - DCOE, or High Availability - HAOE) is provided on a
separate DVD.
The software provided on the SG SMS DVD relies on products and filesets that are provided on
the OE DVD, including HP Serviceguard and the Veritas Storage Foundation products. Each SG
SMS version relies on specific versions of HP Serviceguard and the Veritas Storage Foundation
products that can change with new OE releases.
The software on the SG SMS DVD is installed using swinstall. If an HP-UX OE is installed on
your system and you attempt to install a SG SMS version that is not supported with the versions
of Serviceguard and Veritas Storage Foundation included with the OE, swinstall will detect
the incompatible software and the installation will fail.
The software on the OE DVD is installed using update-ux. If a SG SMS bundle is installed on
your system and you attempt to install or upgrade to an OE version that includes Serviceguard
and Veritas Storage Foundation versions that are not supported with the SG SMS bundle,
update-ux will not detect the incompatible software. The installation will complete, but the
Serviceguard cluster will not start, or you will not be able to access the Veritas volumes.
update-ux does not check for software dependencies.
If the OE upgrade you want to install is not supported with the Serviceguard and Veritas Storage
Foundation versions in the SG SMS bundle that is installed on your system, you must upgrade
to an SG SMS bundle that is supported with the OE version you want to install.
See “Compatibility Information and Installation Requirements” (page 24) for more information
on bundle upgrades.
Known Problems and Workarounds
This section describes known problems and workarounds at the time of this HP Serviceguard
Storage Management Suite Version A.02.00 for HP-UX 11i v3 release. For the most recent
information contact your HP support representative or the Hewlett-Packard IT Resource Center.
Known problems for individual products included in the HP Serviceguard Storage Management
Suite bundles are documented in their respective Release Notes. HP recommends that you read
the Release Notes for individual products included in the HP Serviceguard Storage Management
Suite bundle you plan to install, before beginning the installation. See “Documentation for this
Version” (page 22) for information on related documentation.
38 HP Serviceguard Storage Management Suite Version A.02.00 for HP-UX 11i v3 Release Notes