/ 12.3. FAQs
	12.2. Debugging a HA Cluster		12.4. Fore More Information

FAQs

What is the state of my cluster?

To check the current state of your cluster, use the program crm_mon. This displays the current DC as well as all of the nodes and resources that are known to the current node.

Several nodes of my cluster do not see each other.

There could be several reasons:

Look first in the configuration file /etc/ais/openais.conf and check if the multicast address is the same for every node in the cluster (look in the interface section with the key mcastaddr.)
Check your firewall settings.
Check if your switch supports multicast addresses
Another reason could be, the connection between your nodes is broken. Most often, this is the result of a badly configured firewall. This also may be the reason for a split brain condition, where the cluster is partitioned.

I want to list my currently known resources.

Use the command crm_resource -L to learn about your current resources.

I configured a resource, but it always fails.

Try to run the resource agent manually. With LSB, just run scriptname start and scriptname stop. To check an OCF script, set the needed environment variables first. For example, when testing the IPaddr OCF script, you have to set the value for the variable ip by setting an environment variable that prefixes the name of the variable with OCF_RESKEY_. For this example, run the command:

export OCF_RESKEY_ip=<your_ip_address>
/usr/lib/ocf/resource.d/heartbeat/IPaddr validate-all
/usr/lib/ocf/resource.d/heartbeat/IPaddr start
/usr/lib/ocf/resource.d/heartbeat/IPaddr stop

If this fails, it is very likely that you missed some mandatory variable or just mistyped a parameter.

I just get a failed message. Is it possible to get more information?

You may always add the -V parameter to your commands. If you do that multiple times, the debug output becomes very verbose.

How can I clean up my resources?

If you know the IDs of your resources, which you can get with crm_resource -L, remove a specific resource with crm_resource -C -r resource id -H HOST.

I can not mount an ocfs2 device.

Check /var/log/message if there is the following line:

Jan 12 09:58:55 clusternode2 lrmd: [3487]: info: RA output: (o2cb:1:start:stderr) 2009/01/12_09:58:55 
  ERROR: Could not load ocfs2_stackglue
Jan 12 16:04:22 clusternode2 modprobe: FATAL: Module ocfs2_stackglue not found.

In this case the kernel module ocfs2_stackglue.ko is missing. Install the package ocfs2-kmp-default, ocfs2-kmp-pae or ocfs2-kmp-xen depending on the installed kernel.