Managing Serviceguard Sixteenth Edition, March 2009

concurrent_vgchange_operations
Specifies the number of concurrent volume group activations or deactivations allowed
during package startup or shutdown.
Legal value is any number greater than zero. The default is 1.
If a package activates a large number of volume groups, you can improve the package’s
start-up and shutdown performance by carefully tuning this parameter. Tune
performance by increasing the number a little at a time and monitoring the effect on
performance at each step; stop increasing it, or reset it to a lower level, as soon as
performance starts to level off or decline. Factors you need to take into account include
the number of CPUs, the amount of available memory, the HP-UX kernel settings for
nfile and nproc, and the number and characteristics of other packages that will be running
on the node.
NOTE: If you set concurrent_vgchange_operations to a value greater than 1, you may
see messages such as this in the package log file:
Cannot lock “/etc/lvmconf//lvm_lock” still trying...”
This is an informational message that can be safely ignored.
enable_threaded_vgchange
Indicates whether multi-threaded activation of volume groups (vgchange -T)is
enabled. New for modular packages. Available on HP-UX 11i v3 only.
Legal values are zero (disabled) or 1 (enabled). The default is zero.
Set enable_threaded_vgchange to 1 to enable vgchange -T for all of a package’s volume
groups. This means that when each volume group is activated, physical volumes (disks
or LUNs) are attached to the volume group in parallel, and mirror copies of logical
volumes are synchronized in parallel, rather than serially. That can improve a package’s
startup performance if its volume groups contain a large number of physical volumes.
Note that, in the context of a Serviceguard package, this affects the way physical volumes
are activated within a volume group; concurrent_vgchange_operations (page 277) controls
how many volume groups the package can activate simultaneously.
IMPORTANT: Make sure you read the configuration file comments for both
concurrent_vgchange_operations and enable_threaded_vgchange before configuring these
options, as well as the vgchange (1m) manpage.
vgchange_cmd
Specifies the method of activation for each HP-UX Logical Volume Manager (LVM)
volume group identified by a vg entry (see (page 279)). Replaces VGCHANGE which
is still supported in the package control script for legacy packages; see “Configuring
a Legacy Package” (page 338).
Choosing Package Modules 277