Unable to start one of the VM due to storage domain is not available

Dears can any one explain to me why this happened, I have a RHEV environment with 3 hosts in one cluster connected with one FC Storage and every this is fine, suddenlly, after we make power off to one of VM has RHEL 5.7 cann't boot and stop with error that the inittab is not exist,

whereever other VM's still up and runnign 

I check the Evnet and found this error

VM.xxx is down exit message, Domian not found no domain with matching uuid" xxxx" 

when I tried to boot the VM in rescue mode I found the disk but without any lvm partitions,

I tried to deactivate and activate the disk, withoout any luck, finally I just cloned the vm from the latest snapshoot, and after finish, I started the original VM again as the last try but I found it up and running without any issues, So I just need to know the reasone and how can I prevent it in future.