We need stable device paths for our Twinstrata SAN drives. Many guides for setting up iSCSI connectors simply say to use a device path like /dev/sda or /dev/sdb.

This is far from correct, I doubt that any setup exists that would be happy to have its device name suddenly change (from /dev/sda to /dev/sdb for example).

The fix I found was to install multipath and start a multipathd on boot which then provides a stable mapping between the storage's WWID to a device path like this /dev/mapper/firebird_database. This is a method described in the CentOS/RedHat here: http://www.centos.org/docs/5/html/5.1/DM_Multipath/setup_procedure.html.

This seems a little complicated though. We noticed that it is common to see UUIDs appear in fstab on new installs. So, the question is, why do we need an external program (multipathd) running to provide a stable device mount? Should there be a way to provide the WWID directly in /etc/fstab?