dovecot - Apr 2011 - dict quota problem

Papp Tamas <tompos at martos.bme.hu> wrote:
> On 04/20/2011 01:47 PM, Sven Hartge wrote:
>> "du" also accounts for the metadata of the filesystem. With
Maildir++
>> you have many files per directory which causes the directory inode to
>> increase in size. After mails are deleted, the now empty space inside
>> the directory is not reclaimed (at least not in ext2/3/4, I guess, XFS
>> behaves the same) and you see a difference in size, since dovecot only
>> counts the raw size of the mails.
>>
>> You can test this for yourself: create a directory, place a 100M big
>> file inside and check with "du". Then delete that file,
create 10,000
>> files with 10KB size inside, check with "du", delete the
files and check
>> again.
> Thank you for your prompt answer.
> Why does dovecot count only the raw size? Does this mean, dict quota is 
> not usable with maildirs? Is this true for sdbox also?
In addition to the answer from Timo:

Counting all meta-data is also very unintuitive for the user. Imagine a
user with an INBOX containing 200,000 mails. This will result in a
_huge_ directory inode for the INBOX folder (about 20MB for XFS). Now he
deletes all those mails and expects a quota usage of 0 bytes. But the
quota is still at 20MB, because the directory inode has not been reduced
by the filesystem.

I guarantee you, you will get numerous support calls.

At least I got them while using filesystem-based quotas.

Gr??e,
S?

-- 
Sigmentation fault. Core dumped.

On 04/20/2011 05:26 PM, Sven Hartge wrote:
> Papp Tamas<tompos at martos.bme.hu>  wrote:
>
>> On 04/20/2011 01:47 PM, Sven Hartge wrote:
>>> "du" also accounts for the metadata of the filesystem.
With Maildir++
>>> you have many files per directory which causes the directory inode
to
>>> increase in size. After mails are deleted, the now empty space
inside
>>> the directory is not reclaimed (at least not in ext2/3/4, I guess,
XFS
>>> behaves the same) and you see a difference in size, since dovecot
only
>>> counts the raw size of the mails.
>>>
>>> You can test this for yourself: create a directory, place a 100M
big
>>> file inside and check with "du". Then delete that file,
create 10,000
>>> files with 10KB size inside, check with "du", delete the
files and check
>>> again.
>> Thank you for your prompt answer.
>> Why does dovecot count only the raw size? Does this mean, dict quota is
>> not usable with maildirs? Is this true for sdbox also?
> In addition to the answer from Timo:
>
> Counting all meta-data is also very unintuitive for the user. Imagine a
> user with an INBOX containing 200,000 mails. This will result in a
> _huge_ directory inode for the INBOX folder (about 20MB for XFS). Now he
> deletes all those mails and expects a quota usage of 0 bytes. But the
> quota is still at 20MB, because the directory inode has not been reduced
> by the filesystem.
>
> I guarantee you, you will get numerous support calls.
>
> At least I got them while using filesystem-based quotas.
I'm sorry for the late response.

So, there is no exact or something closer solution with normal maildirs?

Thank you,

tamas