Quote Originally Posted by mnshsnghl View Post
I dont have the configuration wrt fence_scsi right now, coz I started experimenting with something else. I will try this option, but I still dont know even if I configure this option what will trigger unfencing operation to this node ? I read at multiple places -- "The failed node will no longer be able to write to the device(s). A manual reboot is required."
Since reboot was not an option for me, I didnt configure that. But doesnt this sentence mean that a manual reboot needs to be triggered to the node, and during the course of reboot (maybe be before rebooting), the node shall be unfenced.

What I would want is to be able to "unfence" the node without rebooting. Is there a way to do it ? Can a node unfence itself once the issue with the node is resolved ?

Unfencing should be done by pacemaker itself with the meta attribute from the previous comments. Sadly my test cluster is ontop of VmWare and that doesn't support persistent SCSI-3 reservations.
If I have time, I will deploy an iSCSI and try it myself.
Keep in mind that the fence_scsi will automatically detect which LUNs need to be fenced/unfenced if they are part of a volume group with "c" flag (clustered) , but will require the "devices=" if you use HA-LVM (which I prefer as it supports dual corosync rings).