dovecot - Mar 2012 - SIS and restoring from backups

On 2012-03-24 7:49 AM, Timo Sirainen <tss at iki.fi> wrote:
 > This is already optionally done in v2.0+dbox. MIME attachments can be
 > stored in plain binary form if they can be reconstructed back into
 > their original form. It doesn't break any signed stuff.

Hey Timo,

Splitting this off into a separate thread...

On the question of the existing SIS capability for attachments... have 
you given any thought as to how to solve the problem of restoring from 
backups when SIS is used? I was planning on using it initially, until I 
read on list that restoring from (normal disk-to-disk) backups would not 
work when SIS was enabled - this is obviously a deal breaker for anyone 
who relies on backups - which I would think would be almost everyone?

Or maybe I misunderstood the problem?

-- 

Best regards,

Charles

On 24.3.2012, at 14.01, Charles Marcus wrote:
> On the question of the existing SIS capability for attachments... have you
given any thought as to how to solve the problem of restoring from backups when
SIS is used? I was planning on using it initially, until I read on list that
restoring from (normal disk-to-disk) backups would not work when SIS was enabled
- this is obviously a deal breaker for anyone who relies on backups - which I
would think would be almost everyone?
> 
> Or maybe I misunderstood the problem?
You can do full backups from a filesystem snapshot, which works "well
enough" (might leave some unused attachments lying around in some rare
cases, but that can also happen if Dovecot crashes/dies).

The other possibility is to already use dsync (doveadm backup) to do full
backups. With the redesigned dsync you would be able to do incremental backups
also. In any case the solution involves de-SISing mails for backup.