We performed, at a couple of different sites, a migration from UW-IMAP (slow) to dovecot 1.0rcX (blazingly fast) and did a similar step. What we did was audit the main mail server system to determine where all of the .mailboxlist files were, and we created a copy of each of those .mailboxlist files as .subscriptions. In other words, in a given user's home directory, they had a .mailboxlist file and a .subscriptions file just prior to the migration. Immediately after the migration was complete, we removed all of the .mailbox list files from the system (actually, we backed them up first, then removed them).
The migration was seamless to the end user community.
The key element here, though, is that the .mailboxlist and .subscriptions files reside at the top level of the user's home directory ($HOME) regardless of how they have their IMAP root directory configured. The format we've seen of the .subscriptions and .mailboxlist files is: mail/Sent mail/Marketing/Bill ...
The .subscriptions contents are relative to the user's home directory, and the IMAP root directory configured on the client defines the 'filter', so to speak. You may want to take a good look at the contents of your .mailboxlist files to make sure everything will go as planned. If necessary, you can always run them through a perl script to massage them just the right way, but I doubt you would need to. The migration is, after all is said and done, somewhat painless.
-Rich
Steven F Siirila wrote:
Background:
We are a UW-IMAP shop, using mbox format. (!) We are in the process of upgrading to Dovecot, hopefully to 1.0 proper. :) One of the modifications we have been using in test versions of Dovecot involve the move of the user subscription file from:
IMAP-root/.subscriptions
to:
$HOME/.mailboxlist
Rather than having to make changes to Dovecot source code each time a new release comes out, it would seem to make sense to have a way to configure this from dovecot.conf. Something like:
# Default (%i denotes IMAP root): #imap_subscription_file = %i/.subscriptions
# UW-imap-style (%h denotes home directory): #imap_subscription_file = %h/.mailboxlist
While it makes sense to me to have the subscription file where it is in Dovecot by default, it would be a substantial undertaking to determine where to move the .mailboxlist to in our environment for each user, since there is no easy way to determine what a user's IMAP root directory is set to in their client.
Thoughts?