Managing Serviceguard A.11.20, March 2013

Additional Points To Note
Keep the following points in mind.
• When packages are detached, they continue to run, but without high availability protection.
Serviceguard does not detect failures of components of detached packages, and packages
are not failed over. Serviceguard will not provide local LAN failover of IP addresses if the
node has been halted in detach mode.
IMPORTANT: This means that you will need to detect any errors that occur while the package
is detached, and take corrective action by running cmhaltpkg to halt the detached package
and cmrunpkg (1m) to restart the package on another node.
• cmviewcl (1m) reports the status and state of detached packages as detached.
This is true even if a problem has occurred since the package was detached and some or all
of the package components are not healthy or not running.
• Because Serviceguard assumes that a detached package has remained healthy, the package
is considered to be UP for dependency purposes.
This means, for example, that if you halt node1, detaching pkgA, and pkgB depends on
pkgA to be UP on ANY_NODE, pkgB on node2 will continue to run (or can start) while pkgA
is detached. See “About Package Dependencies” (page 142) for more information about
dependencies.
• As always, packages cannot start on a halted node or in a halted cluster.
• When you restart a node or cluster whose packages have been detached, the packages are
re-attached; that is, Serviceguard begins monitoring them again.
At this point, Serviceguard checks the health of the packages that were detached and takes
any necessary corrective action — for example, if a failover package has in fact failed while
it was detached, Serviceguard will halt it and restart it on another eligible node.
CAUTION: Serviceguard does not check LVM volume groups and mount points when
re-attaching packages.
• The detached state and status could appear to persist across a reboot.
If a node reboots while packages are detached (or detaching, or re-attaching), and package
components are left in an inconsistent state, the appropriate package halt scripts will run to
clean things up when the node comes back up. But cmviewcl will continue to show the
packages as detached. Either cmhaltpkg or cmrunnonde (1m) will reset the packages'
state and status.
• If you halt a package and disable it before running cmhaltcl -d to detach other packages
running in the cluster, auto_run will be automatically re-enabled for this package when the
cluster is started again, forcing the package to start.
To prevent this behavior and keep the package halted and disabled after the cluster restarts,
change auto_run to no in the package configuration file (page 239), and re-apply the
package, before running cmhaltcl -d.
• If an IP address is switched to the standby LAN because of a failure of on the primary LAN
before a node is halted in detached mode, and if the failure is detected as an IP-only failure
(meaning that the primary LAN was failed at the IP level only) then the IP address will remain
on the standby LAN even after the node is restarted via cmrunnode. This will also happen
286 Cluster and Package Maintenance