> On Mon, Mar 20, 2006 at 01:16:37PM -0500, Hendershot, Zach wrote: > > Hello, > > I was wondering about various fencing methods. We don't have any > > "supported" hardware available to do proper fencing via the Red Hat > > fencing agents. Other clustered filesystems like the Veritas CFS and > > Oracle's ocfs2 solve the fencing problem by simply panic'ing the > > machine to keep the IO from hitting the disk. > This assumes the machine knows it should fence itself, which isn't always the case. If the machine is hung somewhere and comes > back to life after it's been recovered, it could write and corrupt the fs, a panic doesn't solve this. > > Dave That's a good point, I wasn't thinking. Oracle and (I assume) Veritas do this by relying on a kernel thread that writes out timestamps and if it doesn't write an expected timestamp (and other nodes see it as dead) it panics itself to self-fence. How does RHCS decide if a node is dead? I was under the understanding that if the other nodes don't receive a heartbeat from the node for a timeout period they execute the fence command on the node. I'm interested why that choice was made, was it a technical problem with the above method or a design decision? Have a good one. Zach -- Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
