On Fri, Aug 14, 2009 at 4:47 PM, Harald Dunkel<[email protected]> wrote: > Hi folks, > > If I understood the Linux-HA concept correctly, then it > works because the services (NFS, Samba, EMail, Apache, > etc.) share state information between the cluster hosts > somehow.
"Somehow" is actually more correct than you probably realize. How you chose to make the data available across the machines in the cluster is entirely up to you. Pacemaker doesn't care, it just starts and stops things in the order you define. Some people with bigger budgets use SANs, others use software solutions like drbd and mysql replication. If you take the software approach, then Heartbeat/Pacemaker is also happy to manage those services for you too. So the answer depends very much on the path you took and how you configured the cluster (particularly stonith). > For NFS and Samba this state information is often > stored in a file system on a shared block device, e.g. > using drbd. > > But does this concept work for the file system itself? > AFAICS most Linux file systems keep state information in > RAM. When the backup host takes over because the master > died of something, does it really have consistent > information on file system, service and application > level? > > Sorry for asking. I am highly concerned because I saw > 2 fatal file system failures within the last 7 days (xfs). > > > Regards > > Harri > > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems > _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
