Building Disaster Recovery Serviceguard Solutions Using Metrocluster with Continuous Access for P9000 and XP A.11.00

Limitations of the rolling upgrade for Metrocluster
Limitations of the rolling upgrade for Metrocluster:
• The cluster or package configuration cannot be modified until the rolling upgrade is completed.
If the configuration must be edited, upgrade all the nodes to the new release, and then modify
the configuration file and copy it to all the nodes in the cluster.
• New features of the latest version of Metrocluster cannot be used until all the nodes are
upgraded to the latest version.
• No more than two versions of Metrocluster can be running in the cluster while the rolling
upgrade is in progress.
• The rolling upgrade procedure cannot be used as a means of using multiple versions of
Metrocluster software within the cluster. HP recommends that you upgrade all the cluster nodes
to the latest version as quickly as possible.
• HP Serviceguard cannot be deleted on any node when the rolling upgrade is in progress in
the cluster.
Upgrading the P9000 or XP Raid Manager software for Metrocluster with Continuous
Access for P9000 and XP
To upgrade the P9000 or XP RAID Manager software online without any disruption in the
Metrocluster, follow the instructions included in the HP P9000 RAID Manager User Guide available
at http://www.hp.com/support/manuals -> storage -> Storage Software -> Storage Device
Management Software -> HP XP RAID Manager Software . Metrocluster communicates with P9000
or XP Raid Manager software only when Metrocluster packages are starting up. So, Metrocluster
package failover or package movement must be avoided until all the nodes in the Metrocluster
are upgraded to the same version of the P9000 or XP RAID Manager software. When using the
disk monitoring feature, Metrocluster packages access the RAID Manager instances on the nodes
that the packages are running on. So, in such configurations, ensure that all Metrocluster packages
are moved to a different node prior to updating the P9000 or XP RAID Manager software.
Other considerations on asynchronous mode
The following are additional points to consideration when using asynchronous mode:
• When adding a new volume to an existing device group, the new volume state is SMPL. The
XP disk array controller (DKC) is smart enough to do the paircreate only on the new volume.
If the device group has mixed volume states such as PAIR and SMPL, the pairvolchk returns
EX_ENQVOL, and horctakeover fails.
• If you change the LDEV number associated with a given target/LUN, you must restart all the
Raid Manager instances even though the Raid Manager configuration file is not modified.
• Any firmware update, cache expansion, or board change, requires a restart of all the Raid
Manager instances.
• pairsplit for asynchronous mode might take a long time depending on how long the
synchronization takes. There is a potential for the Continuous Access link to fail while
pairsplit is in progress. If this happens, pairsplit will fail with a return code of
EX_EWSUSE.
• In most cases, Metrocluster/Continuous Access in asynchronous mode behaves the same as
when the fence level is set to NEVER in synchronous mode.
Other considerations on asynchronous mode 81