Doing Cyrus *right* for a large installation

[Pascal Gienger]

Andrew Morgan wrote:

> But then I started thinking about how I was going to backup all this new 
> data...  Our backup administrator isn't too excited about trying to backup 
> 12TB of email data.

Just a side note:

For most backup systems it is not the size which matters much (because
only a small portion of data gets changed each day on a typical IMAP
storage) it is the *NUMBER* of files, because - for an incremental
backup - each file stat data has to be read and compared.

With ZFS (gzip compression activated), we get 31 million files in 3-4
hours (example with tivoli storage manager):

01/03/09   23:38:48 --- SCHEDULEREC STATUS BEGIN
01/03/09   23:38:48 Total number of objects inspected: 31,305,555
01/03/09   23:38:48 Total number of objects backed up:   25,347
01/03/09   23:38:48 Total number of objects updated:          0
01/03/09   23:38:48 Total number of objects rebound:          0
01/03/09   23:38:48 Total number of objects deleted:          0
01/03/09   23:38:48 Total number of objects expired:    308,991
01/03/09   23:38:48 Total number of objects failed:           0
01/03/09   23:38:48 Total number of bytes transferred:    2.56 GB
01/03/09   23:38:48 Data transfer time:                  280.87 sec
01/03/09   23:38:48 Network data transfer rate:        9,594.01 KB/sec
01/03/09   23:38:48 Aggregate data transfer rate:        209.05 KB/sec
01/03/09   23:38:48 Objects compressed by:                   15%
01/03/09   23:38:48 Elapsed processing time:           03:34:49
01/03/09   23:38:48 --- SCHEDULEREC STATUS END
01/03/09   23:38:48 --- SCHEDULEREC OBJECT END SA_SO_MAIL 01/03/09
20:00:00
01/03/09   23:38:48
Executing Operating System command or script:
   /mail/bin/pr_backupsnapshot_off

Just to give you a "real life" number...

Pascal