Hi, if I have a cluster in which only one node do write operations to the storage at the same time, can I use GFS without fence system? Or use the fence system without hardware (such as FC switch, power switch) involved, do the fence operations automaticly immediately after the heartbeat detects a bad node. In reverse, at what condition that data corruption would happen without fence in GFS system? Two nodes write at the same LV|GFS|file|block (which?) at the same time? Thanks for any reply! Luckey.