Managing MC/ServiceGuard NFS for Linux, December 2001

Installing and Configuring MC/ServiceGuard NFS for Linux
Configuring a MC/ServiceGuard NFS Package
Chapter 228
6. Specify that this package uses the high availability NFS server by
uncommenting the HA_NFS_SERVER variable. For example:
HA_NFS_SERVER=”yes”
7. If two packages have the same adoptive node, and you want to
prevent a shared adoptive node from adopting both packages at once,
specify the cmmodpkg command with the package control option (-d)
in the customer_defined_run_cmds. For example:
function customer_defined_run_cmds
{
cmmodpkg -d -n ‘hostname‘ pkg02 &
}
This package control function can prevent an adoptive node from
becoming overloaded when multiple packages fail over. If an
adoptive node becomes overloaded, it can fail.
In this example, if a host is an adoptive node for both pkg01 and
pkg02, the above cmmodpkg -d command, in the control script for
pkg01, would prevent the host that is running pkg01 from adopting
pkg02.
Add a similar line in the control script for pkg02 to prevent the host
that is running pkg02 from adopting pkg01.
The ampersand (&) causes the cmmodpkg command to run in the
background. The cmmodpkg command in the background allows the
control script to complete and finish bringing up the package.
There is a small window of time, during which if one package has
begun to fail over but the cmmodpkg command has not executed, the
other package can fail over and the host will adopt it. In other words,
if two packages fail over at approximately the same time, a host may
adopt both packages, even though the package control option is
specified.
See “Configuring One Adoptive Node to Support Failover of Multiple
Packages” on page 41 for a sample configuration using the package
control option.
8. Use the default values for the rest of the variables in the control
script, or change them as needed. For instructions on modifying the
default values, see the Managing MC/ServiceGuard for Linux
manual, or read the comments in the
/usr/local/cmcluster/nfstoolkit/pkg.cntl template file.