Managing Serviceguard Sixteenth Edition, March 2009

their configuration file, Serviceguard specifies the dependency on the CFS system
multi-node package (SG-CFS-pkg).
CAUTION: Once you create the disk group and mount point packages, it is critical
that you administer the cluster with the cfs commands, including cfsdgadm,
cfsmntadm, cfsmount, and cfsumount. If you use the general commands such
as mount and umount, it could cause serious problems such as writing to the local
file system instead of the cluster file system.
Any form of the mount command (for example, mount -o cluster,
dbed_chkptmount, orsfrac_chkptmount) other than cfsmount or
cfsumountin a HP Serviceguard Storage Management Suite environment with
CFS should be done with caution. These non-cfs commands could cause conflicts
with subsequent command operations on the file system or Serviceguard packages.
Use of these other forms of mount will not create an appropriate multi-node
package which means that the cluster packages are not aware of the file system
changes.
NOTE: The Disk Group (DG) and Mount Point (MP) multi-node packages
(SG-CFS-DG_ID# and SG-CFS-MP_ID#) do not monitor the health of the disk
group and mount point. They check that the application packages that depend on
them have access to the disk groups and mount points. If the dependent application
package loses access and cannot read and write to the disk, it will fail, but that will
not cause the DG or MP multi-node package to fail.
4. You create the CFS package, SG-CFS-pkg, with the cfscluster command. It is
a system multi-node package that regulates the volumes used by CVM 4.1 and
later. System multi-node packages cannot be dependent on any other package.
Planning for Expansion
You can add packages to a running cluster. This process is described in “Cluster and
Package Maintenance” (page 297).
When adding packages, be sure not to exceed the value of max_configured_packages as
defined in the cluster configuration file; see “Cluster Configuration Parameters ”
(page 138). You can modify this parameter while the cluster is running if you need to.
Choosing Switching and Failover Behavior
To determine the failover behavior of a failover package (see “Package Types”
(page 68)), you define the policy that governs where Serviceguard will automatically
start up a package that is not running. In addition, you define a failback policy that
determines whether a package will be automatically returned to its primary node when
that is possible.
Package Configuration Planning 163