[Dovecot] Maildir feature I'd like to see - SSD for newer messages

[Marc Perkel]

SSD drives are very fast but expensive. So I have a crude idea that I'd 
like to see. May not be practical but would like to get some thoughts on it.

Some new SSDs use SATA 3 (6gb/sec) with 355/mb/sec read speeds and 
215MB/sec write. Put these in raid 0 and it screams! Can you imagine how 
fast that would be?

What would be nice is if new email were on faster drives with old email 
being migrated to larger mechanical cheaper storage. Perhaps messages 
over a month old? From dovecot's perspective it would sort of all look 
the same but maybe one a week a script would run migrating older 
messages to slower media.

It would also make backups easier. The faster newer messages could be 
archived hourly. On the weekend after the archiving script was run the 
older message could be backed up once a week.

I'm not sure what it would take to make dovecot seamlessly access email 
from two different locations or if this is practical. Just wanted to 
throw the idea out there to see if something sticks.