GFS2 & CLVM

GFS needs to go together with CLVM according to the following Red Hat KB. Otherwise Red Hat won't support any problem for GFS.

https://access.redhat.com/site/solutions/46637

Rocks Cluster Installation Problems

Yes, I am damn stupid enough to screw up Rocks Cluster Installation that is as easy as ABC. Here is culprits giving me headache for 2 days -

1. Never ever try LVM during installation. Or your installation will fail with some python error. But you can use LVM on other harddisks after installation. 
2. Don't use ".local" as domain suffix for frontend node. I used "headnode.local" for my frontend hostname. Installation went through well without complaining anything. However, server came up without public network/interface after installation finished. I had been barking the wrong tree for 1 and half day checking switch, using lower version of Rocks and using different IP schema. Finally, I used other FQDN like ".netlynker.net" and it solved the issue.

Really hope this post helpful for somebody out there. :D