We had an issue during an LPM of a cluster node that seemed to be a network related issue. After that we rebooted everything and brought it all back up but now both nodes of the cluster don't see either as being "up" (clstat). They see themselves but not the other node. One of the odd issues is that the cl_clcmd will execute a command on both nodes. I can also start cluster services on both nodes from one node. This is an active/active setup running cluster version 6.1.0 sp14
Here is an IBM LPM tutorial:
Basic understanding and troubleshooting of LPM
Hope this helps a little.
Please post back and let us know if that tutorial was helpful or not.
Thanks.
PS: Also see attached IBM presentation, which might help: Live Partition Mobility (LPM)
clstat is sometimes a real pain to work with as it requires a lot of things to 'just work' so to say.
Your cluster can be fine and clstat doesn't respond. There's this handy note from ibm: IBM Common issues causing clstat to malfunction
There's other resources / blog posts about getting clstat talking again and I suggest digging into them. Gotta run to so can't post them all here right now.