I currently have two exchange 2003 servers. one is my primary and the other is a front end server used for OWA. All mailbox store reside on the primary exchange server which is connect to a san. I would like to know if it is possible to demount the san drive from the primary exchange server and add the san drives to the OWA exchange server. I would like to know if this is possible, in an event that we shut down out primary exchange server and it does not come back up. Can this be done? All comments and suggestions are appreciated.

No. The database is not portable. If your back-end, mailbox server fails you will have to restore from backup while you users are in cached mode. To mitigate downtime, users could be working from a dial tone database you create (after some reconfiguration of the front-end) while you are restoring the back end. If you want fault tolerant back-end mailbox servers you need to use a cluster. or another 3rd party option like doubletake or neverfail. http://www.msexchange.org/tutorials/Exchange-Dial-tone-Restore-Method-Part1.html