Managing MC/ServiceGuard NFS A.11.11.03 and A.11.23.02 (June 2004)

Installing and Conﬁguring MC/ServiceGuard NFS

Conﬁguring an MC/ServiceGuard NFS Package

Chapter 2 39

The path name for the executable script does not have to be unique to

each package. Every package can use the same script. Multiple

instances of the monitor script can run on the same node without any

problems, and if a package fails over, only the instance associated

with that package is killed.

If you do not want to run the NFS monitor script, comment out the

NFS_SERVICE_NAME and NFS_SERVICE_CMD variables:

# NFS_SERVICE_NAME[0]=nfs.monitor

# NFS_SERVICE_CMD[0]=/etc/cmcluster/nfs/nfs.mon

By default, the NFS_SERVICE_NAME and NFS_SERVICE_CMD variables

are commented out, and the NFS monitor script is not run.

7. If two packages have the same adoptive node, and you want to

prevent the adoptive node from adopting both packages at once,

specify the cmmodpkg command with the package control option (-d)

in the customer_defined_run_cmds.

function customer_defined_run_cmds

{

cmmodpkg -d -n ‘hostname‘ pkg02 &

}

The package control option 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. A similar

line in the control script for pkg02 could prevent the host that is running

pkg02 from adopting pkg01. The ampersand (&) causes the cmmodpkg

command to run in the background. It must run in the background to

allow the control script to ﬁnish bringing up the package. The cmmodpkg

command will hang until the package is up, so it must run in the

background to allow the control script to complete.

There is a short time, after one package has failed over but before the

cmmodpkg command has executed, when 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.

B5140-90020.book Page 39 Thursday, June 3, 2004 5:04 PM