HP Serviceguard for Linux Version A.11.18 Release Notes, 2nd Edition, March 2009

• Make sure that all applications that run on the current OS will also be supported
with the new OS.
• Verify that the new OS supports the current cluster hardware configuration and
drivers (network interfaces, bonding driver, shared disk storage. etc.).
NOTE: If there is no HP bonding driver for the Linux version you are using, use
the bonding driver supplied with the Linux distribution.
• Do a full backup on each node.
NOTE: HP recommends you use the rolling upgrade process if possible, because it
keeps your mission-critical applications running; and also that you update the software
(rather than do a cold install) if possible, because updating preserves the current OS
and cluster configuration. But make sure you read “Limitations ” (page 67) before you
start the upgrade, and keep in mind that the entire upgrade process has to complete
successfully before you can use any Serviceguard commands.
CAUTION: If a failure occurs on one node while you are upgrading another, packages
- and the applications they contain - may not be able fail over to the node being
upgraded.
Limitations
The following limitations apply to rolling upgrades:
• During rolling upgrade, you should issue Serviceguard commands (other than
cmrunnode and cmhaltnode) only on a node containing the latest revision of
the software. Performing tasks on a node containing an earlier revision of the
software will not work or will cause inconsistent results.
• You cannot modify the cluster or package configuration until the upgrade is
complete. You cannot modify the hardware configuration—including the cluster’s
network configuration—during rolling upgrade. This means that you must upgrade
all nodes to the new release before you can modify the configuration file and copy
it to all nodes.
• None of the features of the newer release of Serviceguard are allowed until all
nodes have been upgraded.
• Binary configuration files may be incompatible between releases of Serviceguard.
Do not manually copy configuration files between nodes. The Serviceguard binary
configuration file(cmclconfd) must be in the correct directory or the cluster will
not behave properly.
• Within a Serviceguard cluster, no more than two versions of Serviceguard can be
running while the rolling upgrade is in progress.
Compatibility Information and Installation Requirements 67