[Dovecot] dsync is SLOW compared to rsync

[ncjeffgus]

On Thu, 29 Mar 2012 07:04:26 +0300, Timo Sirainen wrote:
> On 29.3.2012, at 5.07, Jeff Gustafson wrote:
>
>> 	That fixed some errors, but it still is having some sort of trouble
>> with that command:
>>
>> # time doveadm -o mail=maildir:/home/bu/user.mdbox import -u
>> user at domain.com maildir:/home/users/user%domain.com/Maildir/ "" all
>> doveadm(user at domain.com): Error: Can't find namespace for mailbox 
>> Trash
>> doveadm(user at domain.com): Error: Can't find namespace for mailbox 
>> test
>
> Oh, you don't have prefix="" namespace? If you have e.g.
> prefix="INBOX." namespace then use:
>
> time doveadm -o mail=maildir:/home/bu/user.mdbox import -u
> user at domain maildir:/home/users/user%domain.com/Maildir/ INBOX all

Oh! I should have known that was the problem.
This was very, very fast. This test is maildir to maildir:

# time doveadm -o mail=maildir:/home/bu/test import -u user at domain.com 
maildir:/home/users/user%domain.com/Maildir INBOX all

real	0m0.412s
user	0m0.036s
sys	0m0.088s

But it was just as slow to import into mdbox:

# time doveadm -o mail=mdbox:/home/bu/test2 import -u user at domain.com 
maildir:/home/users/user%domain.com/Maildir INBOX all

real	7m12.738s
user	6m46.161s
sys	0m7.046s

mbox... still pretty fast:

# time doveadm -o mail=mbox:/home/bu/test3 import -u user at domain.com 
maildir:/home/users/user%domain.com/Maildir INBOX all

real	0m58.534s
user	0m52.264s
sys	0m5.762s

sdbox seems a little on the slow side too:

# time doveadm -o mail=sdbox:/home/bu/test4 import -u user at domain.com 
maildir:/home/users/user%domain.com/Maildir INBOX all

real	6m11.616s
user	6m6.924s
sys	0m4.579s

Does information help? It seems that [sm]dbox is on the slow side for 
the purpose of doing backups.

...Jeff