Adding archiving to an existing Cyrus installation

Friends,
I have a client with Cyrus 2.5.10 installed.  Last year we migrated 
their old 2.3.18 system to 2.5.10, with an eye towards an eventual move 
to 3.0.x.  Based on Bron's most excellent email of last year, ([Subject: 
Cyrus database and file usage data] from Cyrus Devel of 8 January 2016) 
we used a tiered layout for the storage:

The main categories are:

  * Config directory (ssd) [/var/lib/imap]
      o sieve
      o seen
      o sub
      o quota
      o mailboxes.db
      o annotations.db
  * Ephemeral [/var/run/cyrus -- in tmpfs]
      o tls_sessions.db
      o deliver.db
      o statuscache.db
      o proc (directory)
      o lock (directory)
  * Mailbox data [typical 2.5.X usage]
      o Meta-data (ssd)
          + header
          + index
          + cache
          + expunge
          + squat (search index)
          + annotations
      o Spool data (disk: raidX)
          + messages (rfc822 blobs)

We sized the Fast SSD pool (this is three-drive mirrors on ZFS) to be 
extra large, so it could eventually handle "Hot" data, and left about 
300GB free there.  Data, on spinning media, is currently 5.74TB with 
4.8TB free (RAID10).  Metadata is 35GB and /var/lib/imap is 8GB, all of 
which is in the Fast pool.

Now the client is ready to take the dive into v3.0, and I'm trying to 
figure out how to put "archive" operation in effect.

I have read the documentation (hell, I wrote most of it) and understand 
the settings, but what I cannot quite wrap my brain around is this: 
There is already all of this data sitting in all of these data 
partitions (we use a total of 34 separate partitions each for data & 
metadata) so how do I make the transition to separate archive 
partitions, since all that data is on the "slow" drives? Can I just 
reassign all of the current data partitions to archivedata partitions, 
define the new set of "Hot" data partitions on the Fast pool, and let 
'er rip, or what?

I promise, if you tell me, I'll write it up as real documentation. :-)

Cheers,
     -nic

-- 
Nic Bernstein                             [email protected]
Onlight, Inc.                             www.onlight.com
6525 W Bluemound Road, Suite 24           v. 414.272.4477
Milwaukee, Wisconsin  53213-4073

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