Hi, I'm running an Exchange 2003 cluster (A/P), with the databases residing on shared disk resources on our EMC SAN. I'm getting ready to move the database files over to a different SAN (IBM). I have 15 databases, ranging in size from 50GB to 500GB, and they add up to a total of 1.6TB. Given the amount of data to move, I'm trying to find out the best way to accomplish this. I know there are three ways I can move the databases - 1. Using ESM, change the database and log path locations, let it dismount the stores and move the files. 2. Use ESEUTIL with the /Y switch to copy the files, then update the database and log path locations in ESM. 3. Use Robocopy to copy the files, then update the database and log path locations in ESM. With options 2 and 3, since I'm copying the files rather than moving them, I'll be able to quickly back out of the change by pointing the database and log file paths back to the old SAN, as long as I've got all Exchange services stopped while I'm doing this. Is this correct? Other than this, what are some other advantages/disadvantages of the three options? Thanks in advance for any insight....

If feasible and you have the downtime to do this I would do. Dismount the databases Disconnect EMC LUNs Move data via SAN to SAN copy keeping and folder structure the same. Reconnect IBM LUNs using same drive letters. Remount the databases This makes it alot easier than using ESM or do some type of file copy from the OS. Most SAN vendors have the ability to copy data to anther location. If you can do this method then I would use either option 1 or 3 in your post.Sr. Exchange Engineer - Constellation Energy