Correct me if I am interpreting this question incorrectly, but it
sounds to me that the OP is asking to about moving the physical
location of the DB files from local drives to SAN not to move the DB
to another server. You would not be changing any content DB GUIDs,
SSP relations or anything that SharePoint cares about, you are only
changing where SQL is looking for the data files for a DB.
I have moved an entire MOSS farm from a virtual SQL server to a
physical one using this technique, along with renaming the physical
SQL server to the same name as the original virtual server.
The steps I would follow are (I am assuming that you are moving all
of the DBs to the SAN):
Shut down the SharePoint servers but not the SQL Server.
Then for each of the SharePoint related DBs, not the SQL system
related DBs:
Detach the DB
Move the DB data files to their new location
Attach the DB files in their new location
Start up the SharePoint Servers.