Managing HP Serviceguard for Linux, Tenth Edition, September 2012

• You cannot detach a package that has relocatable IP addresses on a subnet that is
not configured into the cluster.
Such addresses will not be handled properly when the package is attached or
re-attached.
IMPORTANT: HP does not recommend such configurations. See “ip_subnet”
(page 214).
• You cannot detach packages when the HP-UX Clustered I/O Congestion Control
feature is enabled.
• As of the date of this manual, you cannot detach ECMT-based packages.
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 130) 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
Halting a Node or the Cluster while Keeping Packages Running 249