> What about configuring a cluster without fencing? is it possible? I am > about to create a cluster but with out fencing device. Generally its dangerous. if the servers get out of sync and both try to mount a shared resource, you can end up with corrupted file systems. since the primary goal of a high availability cluster is, well, high availability, and increased overall system reliability, these clusters have to be constructed very carefully or they can cause more problems than they solve. what sort of shared resources will this HA cluster have? how is the shared storage connected ? if its via a iSCSI SAN, you can implement fencing via either the ethernet switch (tell the switch to drop the standby server from the iscsi vlan), or via the storage controller (tell the iscsi target host to disallow LUN access by the current standby server). If its a fiberchannel SAN you can fence via the SAN switch.