On Tue, 22 Jun 2004, Etienne Goyer wrote: > Tore Anderson word of wisdom where : > > There's a third option, which is the one I prefer the most: shared > > block device. > > Well, I did not consider that option since the SAN become a single > point-of-failure, and that is a big no-no according to the > specifications I have at the moment. > > If it would have been possible, it would have been my first choice though.
Most SANs are not single points of failure, unless you consider the whole SAN catching fire a single point of failure. A properly designed SAN can have complete hardware redundancy, so unless you commit some administrator error... :) We have a SAN that we use for user home directories here built from Sun T3 Enterprise pairs. It uses RAID 5 for disk redundancy, has two FC controllers that can failover to each other, has redundant FC links to a pair of FC switches, and the server has redundant FC links to the switches. We've had both disks and controllers fail without even a hiccup, and we've even added more storage to the SAN *and* expanded the file system on the fly. Veritas Volume Manager and File System are wonderful. Andy --- Cyrus Home Page: http://asg.web.cmu.edu/cyrus Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html