Managing HP Serviceguard A.11.20.10 for Linux, December 2012

7.3.3 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.
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.
• 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, mount points, and relocatable
IP addresses when re-attaching packages.
• 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 107) for more information about
dependencies.
• As always, packages cannot start on a halted node or in a halted cluster.
• When a node having detached packages is back up after a reboot they can:
Rejoin the cluster and the detached packages can move to "running" or "failed" state. If
the detached packages are moved to running state, then they must be halted and rerun
as they may have several inconsistencies post reboot.
◦
◦ Not rejoin the cluster and the detached packages remain detached. Such packages must
be halted and rerun to avoid any inconsistencies that can be caused due to the reboot.
• 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 170), and re-apply the
package, before running cmhaltcl -d.
7.3.4 Halting a Node and Detaching its Packages
To halt a node and detach its packages, proceed as follows:
1. Make sure that the conditions spelled out under “Rules and Restrictions” (page 205) are met.
7.3 Halting a Node or the Cluster while Keeping Packages Running 207