Yale University will convert from UWash to Cyrus IMAP email service in Q2-2008.
Searching for Cyrus ref's, I know that UFla, Cornell, Buffalo, MPI-FKF, and 
Uni-Ulm responded to BostonU's 2006-05-16 request for Cyrus backup/restore 
advice.  I hope you and others w/large Cyrus experience will respond again!

We plan to have 10 Cyrus email backend servers (each w/10*200GB FileStores) 
clustered in two primary datacenters, here and there.  The five Cyrus backends 
here will backup to a dedicated TSM service there, and vice versa.  Current 
testing indicates that a DR restore of a single 200GB FS from TSM continuous 
incremental backups on LTO3 tapes will probably take longer than a week to
complete!  Obviously, we need a better backup & restore plan.

From previous responses, other sites were using or considering a combination of 
periodic Image/Full backups w/ more recent incremental backups (on tape or 
Vtape) to optimize restore times.  We do not have Vtape here yet, but are 
interested if you have a Vtape solution that you like for Cyrus backups.

Meanwhile, I currently plan to try to backup each 200GB FS as follows:
        a weekly Mode=Absolute backup (regularly on some weekday, M-F)
        daily incremental backups (on the other days)
all under the same TSM client node using a Cyrus Backup Mgmtclass w/
        VerExists=15 VerDeleted=5  RetExtra=60 RetOnly=90
hoping to effectively replicate our current UWash Backup Mgmtclass w/
        VerExists=8  VerDeleted=2  RetExtra=90 RetOnly=90

If you have already tried this or you have a better recommendation, please 
reply (or send a phone# and time(s) if you would rather talk than type... and 
I'll call you at your convenience.)

Thanks for your consideration.
--
Jim.Owen AT Yale DOT Edu   (203.432.6693)