Installation guide

The Po st - Fail D elay parameter is the number of seconds the fence daemon (fenced)

waits before fencing a node (a member of the fence domain) after the node has failed. The

Po st - Fail Delay default value is 0. Its value may be varied to suit cluster and network

performance.

The Po st - Jo in D elay parameter is the number of seconds the fence daemon (fenced)

waits before fencing a node after the node joins the fence domain. The Po st - Jo in Delay

default value is 3. A typical setting for Po st - Jo in Delay is between 20 and 30 seconds,

but can vary according to cluster and network performance.

Enter values required and Click Apply for changes to take effect.

Note

For more information about Po st - Jo in Delay and Po st - Fail Delay, refer to the

fenced(8) man page.

3. Mu lt icast tab — This tab provides an interface for configuring these Mu lt icast

Co n f ig u rat io n parameters: Let clu st er ch o o se t h e mu lt icast ad d ress and Sp ecif y

t h e mult icast ad d ress man u ally. The default setting is Let clu st er ch o o se t h e

mult icast ad d ress. If you need to use a specific multicast address, click Sp ecif y t h e

mult icast ad d ress man u ally, enter a multicast address into the text box, and click Apply

for changes to take effect.

Note

IPV6 is not supported for Cluster Suite in Red Hat Enterprise Linux 5.

If you do not specify a multicast address, the Red Hat Cluster software (specifically, cman, the

Cluster Manager) creates one. It forms the upper 16 bits of the multicast address with 239.192

and forms the lower 16 bits based on the cluster ID.

Note

The cluster ID is a unique identifier that cman generates for each cluster. To view the

cluster ID, run the cman_tool status command on a cluster node.

If you do specify a multicast address, you should use the 239.192.x.x series that cman uses.

Otherwise, using a multicast address outside that range may cause unpredictable results. For

example, using 224.0.0.x (which is "All hosts on the network") may not be routed correctly, or

even routed at all by some hardware.

Note

If you specify a multicast address, make sure that you check the configuration of

routers that cluster packets pass through. Some routers may take a long time to learn

addresses, seriously impacting cluster performance.

⁠Chapt er 3. Configuring Red Hat Clust er Wit h Conga