I know I that I posted this on Friday and it's only been one working weekday since my post, but I'm just bringing it up again as a reminder that there should be a technical article on this. I have six years worth of message archive data for a few clients, and one domain alone is storing about 130 GB of archived email. As you may imagine, It isn't unreasonable to expect many SM admins are faced with this storage issue as archives continuously grow and will eventually outstrip server capacity thus requiring expansion/migration. Since I am now in the process of moving all archived message data to a separate partition from the message store, it will be easier to manage the storage subsystem in future.
However, I think that at the minimum there should be an approved procedure from SmarterTools on doing this. At best, SmarterTools should improve the process so that migration/move can be done from within the system, not just changing the path to the archive folder, but moving existing archive data from the old location to a new location.
The process I'm using works, but it's a bit of a hassle to restart the SM service every time I move a domain's archive location.