incremental mailbox syncs for quick migration

Hi all,

We are facing quite large mailboxes (>10GB) in our migration from cyrus to dovecot. I did a test on one mailbox and repeated the sync a couple of times with the expected result that the second, third, etc. sync took only seconds compared to minutes for the first sync. We use this command to sync a mailbox:

doveadm backup -R -u USER imapc:

Are there any problems to be expected when we first do a sync for all mailboxes but do not migrate the users right away but instead do the actual migration using a second sync?

Cheers,

j.hofmüller http://thesix.mur.at/