[whishlist] new option for 'doveadm purge'

[Aki Tuomi]

On 8.12.2019 22.10, Michael Grimm via dovecot wrote:
> Hi,
>
> I do store mail in mdbox format of 150m in size (dovecot 2.3.9). 
>
> Once in a while I do experience mdbox files of smaller size, even after applying 'doveadm purge' and previous expunges by the users. like:
>
> -rw-------  1 vmail  dovecot  104854595 Feb  9  2019 /var/mail/.maildirs/userX/storage/m.22
> -rw-------  1 vmail  dovecot   29088478 Mar  8  2019 /var/mail/.maildirs/userX/storage/m.31
> -rw-------  1 vmail  dovecot   98210890 Mar 20  2019 /var/mail/.maildirs/userX/storage/m.39
>
> (Currently the counter is at file number 129.)
>
> Well, I never experienced missing mail or alike, but these "holes" in filesize irritates me, and yes, it is more or less a cosmetic issue. 
>
> Nevertheless, I do sometimes want to get rid of these "holes" by backing up all mail and re-injecting the backup into a vanilla account of that user. And I used this approach when I wanted to store all mail messages in larger mdbox files; again, rather a cosmetic issue.
>
> BUT that takes a very, very long time contrary to the speed of 'doveadm purge'. Unfortunately, that command starts somewhere with more recent mdbox files and never from scratch (oldest mdbox file).
>
> Whishlist: Would it be much of an effort to implement an option like:
>
> 	'doveadm purge -f' 
> 	and '-f' standing for 'force' or 'from scratch' or 'from the very first message found' or 'you name it'?
>
> Thanks in advance and thanks for Dovecot and with kind regards,
> Michael
>
What purge does is that it removes mails that have refcount=0, so "from
scratch" makes no sense. Renumbering the files "for neatness" is rather
heavy operation, as you'd need to move mails around quite a lot. This is
very little benefit to just cater for holes.


Aki