[Dovecot] Hardware infrastructure for email system

[Alex Crow]

On 23/06/12 18:09, Andrzej A. Filip wrote:
> On 06/23/2012 01:23 PM, Reindl Harald wrote:
>> Am 23.06.2012 13:09, schrieb Wojciech Puchar:
>>> Finally i would recommend to get rid of RAID6. It's terribly slow on writes and
>>> writes are common on mail server.
>> depends, it is slower than RAID5, but safer
>>
>>> Buy cheapest but largest SATA drive and use RAID1 (or RAID1+0) setup.
>> oh no please do not recommend SATA crap with RAID1 and think
>> it is faster than RAID6 - the additional writes doe snot mat
>> if the whole disk-system is much faster and RAID1 has no benefit
>> in performance
>>
>> nobody will use SATA disks for high peformance servers in
>> production - really nobody these days!
> Could you specify/define your idea of "high performance servers" land
> border?
> It may reduce the flame war.
>

Hi,

With dovecot, you can separate indexes and email, and with dbox/mdbox, 
have ALT storage, so for instance you could keep your indexes in a 
RAID10 of SSDs, recent email on a RAID10 of 10kRPM/15kRPM SAS drives, 
and older email can go on a load of 5k/7.2k SATA drives in RAID6, or on 
a NAS via NFS.

Note: with *dbox your indexes are the only place your mail flags are 
kept, so don't risk a single drive or even RAID5 for your index store.

This is what I am moving into production from dovecot 1.x on a single 
RAID6 array (hardware, LSI controller, 6 10k SAS drives in RAID10) which 
has served very well for a while but is not getting too small for all 
our mail. Performance has been good for up to 350 users, average mailbox 
size >4G, about 25-35k incoming mails per day.

Cheers

Alex

-- 
This message is intended only for the addressee and may contain
confidential information.  Unless you are that person, you may not
disclose its contents or use it in any way and are requested to delete
the message along with any attachments and notify us immediately.

"Transact" is operated by Integrated Financial Arrangements plc
Domain House, 5-7 Singer Street, London  EC2A 4BQ
Tel: (020) 7608 4900 Fax: (020) 7608 5300
(Registered office: as above; Registered in England and Wales under number: 3727592)
Authorised and regulated by the Financial Services Authority (entered on the FSA Register; number: 190856)