Cyrus Quota vs. du

[Simon Matter]

>
> On May 2, 2007, at 8:51 AM, Dana Canfield wrote:
>
>> We've been slowly phasing in mail quotas and I've discovered that
>> the quota usage reported by cyrus doesn't match a du for that same
>> user.  In fact, I can't find any user where the reports *do*
>> match.  Is this a sign of quota corruption, or am I overlooking
>> something about how the quotas work?
>>
>> Here are some examples to show what I'm checking:
>>
>> [root at balrog ~]# du -s /var/spool/imap/e/user/efreem
>> 1068664 /var/spool/imap/e/user/efreem
>> [root at balrog ~]# du -s /var/spool/imap/a/user/austin
>> 1178924 /var/spool/imap/a/user/austin
>>
>> [root at balrog efreem]# cyradm --user cyrus localhost
>> localhost.localdomain> lq user.efreem
>> STORAGE 904193/2000000 (45.20965%)
>> localhost.localdomain>  lq user.austin
>> STORAGE 703056/1000000 (70.3056%)
>
> The du utility reports usage in terms of blocks, not bytes. This is a
> major drawback of maildir type systems, they can have nasty partial
> block overheads.

Things like delayed expunge can also increase the difference between du
and quota.

Simon