overview zlib efficiency? Summary and added note
Harald Leithner
leithner at itronic.at
Wed Mar 16 09:48:11 UTC 2016
Hi,
use "doveadm" to get all real message
doveadm -f table fetch -A "size.physical" ALL | awk
'{s+=$2}END{printf("%.2fMB\n", s/1024/1024);}'
189247.67MB .. 185G
use "du" to get size on disc:
In my case
with deduplication:
/srv/stroage/# du -s -h *
53G vmail
75G vmail_sis
without deduplication
/srv/stroage/# du -s -h -l *
53G vmail
209G vmail_sis
j4i, SIS can't use the zlib plugin so the 75G in my case are not
compressed (I haven't a filesystem that I trust and has a compression
feature). Anyway it has a 3:1 ratio in my case.
Maybe I interpret the SIS wrong and SIS couldn't be counted with du -l
(count links).
But if someone doesn't have SIS this values should be point you into the
right direction.
bye
Harald
Am 16.03.2016 um 08:50 schrieb Götz Reinicke - IT Koordinator:
> Am 15.03.16 um 16:01 schrieb Götz Reinicke - IT Koordinator:
>> Hi,
>>
>> may be someone has already done that: Do you have a script(?) tool which
>> shows the efficiency of the mail compression if zlib is used?
>>
>> Something that shows the uncompressed size vrs. the compressed.
>
> Hi,
>
> maybe my question was a bit misleading. But anyway thanks for your
> feedback regarding your experiences and compression rates.
>
> We already thought about the benefit of less IO and more CPU power,
> which is no concern.
>
> The mailboxes I checked also go with 40-60% compression rate.
>
> But what I was looking for was a tool or way to see what volume would be
> used if we where not using compression.
>
> e.g. "du -hs --without-zlib"
>
> Our management would like to see a graph one day which shows the volume
> uncompressed and compressed ...
>
> Adding zlib with mdbox or maildir - as we do it currently - is from my
> POV if you have the CPU power a MUST :)
>
> happy dovecoting - Götz
>
>
>
--
Harald Leithner
ITronic
Wiedner Hauptstraße 120/5.1, 1050 Wien, Austria
Tel: +43-1-545 0 604
Mobil: +43-699-123 78 4 78
Mail: leithner at itronic.at | itronic.at
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