Bowie Bailey wrote: > Graham Wood <mailto:gwood@xxxxxxxxxxxxxx> wrote: > >>>Can I just drop the "two_node" definition for a 3-node cluster to >>>force it to keep running with only one node? >> >>If you're looking at GFS, then this arrangement is almost definitely >>going to fry the data in the partition - which will take the system >>down for you permanently. >> >>Imagine that the 3 nodes lose communication (but all three are still >>running) - they're all going to reply the logs from the other two, and >>then start writing to the shared filesystem as if they were the only >>ones in the cluster. >> >>Which will corrupt the GFS very quickly. > > > Isn't that what fencing is supposed to take care of? Maybe I'm not > understanding how this all works together. No, because fencing has to be done by one of the cluster nodes. And the cluster must be quorate to fence another node - otherwise it could be an isolated node fencing the valid part. > What I will have is three nodes. Two that actively use the data in the > shared storage and one node that handles backups. > > The backup node is not critical and could be down at any time for a > number of reasons. I want to make sure that if the backup node is down > and one of the other nodes crashes, that the one remaining node will > continue to be able to access the data in the GFS. > -- patrick -- Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
