[Dovecot] mdbox packing

[Daniel L. Miller]

On 5/6/2012 8:09 PM, Daniel L. Miller wrote:
> On 4/30/2012 5:23 PM, Timo Sirainen wrote:
>> On Mon, 2012-04-30 at 12:43 -0700, Daniel L. Miller wrote:
>>> Is there a way to manually force an mdbox storage to be rebuilt into 
>>> new
>>> files?  Particularly files of the maximum size?
>> You could do it with dsync.
>>
>>
> dsync seems to do a marvelous job - new question.?
>
> Given a mailbox with a larger number of older mails - assuming any new 
> mails will have later dates - will the new mail storage files be 
> identical?  I'm probably not saying the right - let me try this:
>
> 1.  "dsync backup mdbox" (with appropriate args) is run for a given user.
> 2.  "dsync mirror mdbox" is done just to catch up.
> 3.  Old mailstore moved off.
> 4.  New mailstore moved to active location.
>
> I'm sure there's a safer way to do the above - but I've got a 
> low-traffic site and I can just shut down mail service altogether for 
> a few minutes if I want during this.
>
> Now - repeat the above four steps.  Will mail files m.1 through 
> m.(n-1) be identical to the last run?  Is this a valid packing 
> strategy prior to performing an rsync type backup - assuming no 
> changes are being made to the archived mails between pack runs?

Given the above, and SIS - if the backup is performed in the same spool, 
i.e. original is /var/mail/domain/user, backup is 
/var/mail/domain/user-new - will this result in any problems with SIS?  
If after the pack and rename operation, the old mail tree is simply 
deleted - will that leave SIS files unreferenced if the user later 
deletes the messages from their active store?

-- 
Daniel