I am currently on Exchange 2003. I just got a new SAN, and I'm being asked to set up iSCSI and migrate my Exchange 2003 mailboxes to the SAN. I would like to start an upgrade/migration to Exchange 2010 in the next 6 months. My question is, if I migrate the 500 gigs worth of Exchange mailboxes to a new information store on the SAN, can I bring up a new Exchange 2010 server, shut down the Exchange 2003 and mount the information store on the SAN from Exchange 2010, or am I faced with having to migrate 500 gigs worth of mailboxes again this year? I think I know what the answer is - migrate mailboxes from 2003 to 2010. If this is the case, I'm going to try to stall the migration of Exchange 2003 mailboxes to a new information store on the SAN. Seems like a huge waste of time and I'm going to chew up my resources on the SAN and will have to buy another shelf for it sooner as opposed to later. Thanks, Joel

You cannot remount the Exchange 2003 information store with Exchange 2010. You will have to migrate the 500 GB worth of mailboxes. The main reason is that the store architecture is redesigned. Store Architecture changes in Exchange 2010 and Benefits http://www.messagingtalk.org/store-architecture-changes-in-exchange-2010-and-benefitsMCTS: Messaging | MCSE: S+M

Thanks. I figured so. To me, the upgrade is too close to justify migrating all those mailboxes today, only to have to migrate them again soon.