dovecot - Jun 2008 - 1 week after full migration to 1.1v

Ehlo all,

I've been working on a migration of about 240K users from one server
with qmail, courier imap, maildrop and ldap to postfix, dovecot, lda
+sieve. Before the migration the server and the storage were always on
high load. 


Before migration:

Storage IOPs = 4600
Read average  = ?2800
?Write average = 1800

Storage CPU (Raid5)  
Crl0 = 50%
Crl1 = 50%

Server Load = 120
%user = 35
%system = 60
%iowait = 5
%idle = 0

After migration:

?Storage IOPs = 3000
Read average  = ?1200
?Write average = 1800

Storage CPU (Raid5)  
Crl0 = 40%
Crl1 = 40%

Server Load = 25
%user = 10
%system = 27
%iowait = 40
%idle = 23

And now the server responds so quickly to any imap command.


Dovecot is now the default imap/pop server here,? Thanks Timo.


[]s,

Raphael Costa

Hi Raphael,

Can you also share the figures on the average mailbox size and number of 
cocurrent users in peak hour before and after migration? What is your 
hardware configuration (CPU / MEMORY / DISK TYPE )?

- Joe

----- Original Message ----- 
From: "Raphael Bittencourt S. Costa" <raphaelbscosta at
gmail.com>
To: "dovecot" <dovecot at dovecot.org>
Sent: Monday, June 23, 2008 10:36 PM
Subject: [Dovecot] 1 week after full migration to 1.1v

> Ehlo all,
>
> I've been working on a migration of about 240K users from one server
> with qmail, courier imap, maildrop and ldap to postfix, dovecot, lda
> +sieve. Before the migration the server and the storage were always on
> high load.
>
>
> Before migration:
>
> Storage IOPs = 4600
> Read average  = ?2800
> ?Write average = 1800
>
> Storage CPU (Raid5)
> Crl0 = 50%
> Crl1 = 50%
>
> Server Load = 120
> %user = 35
> %system = 60
> %iowait = 5
> %idle = 0
>
> After migration:
>
> ?Storage IOPs = 3000
> Read average  = ?1200
> ?Write average = 1800
>
> Storage CPU (Raid5)
> Crl0 = 40%
> Crl1 = 40%
>
> Server Load = 25
> %user = 10
> %system = 27
> %iowait = 40
> %idle = 23
>
> And now the server responds so quickly to any imap command.
>
>
> Dovecot is now the default imap/pop server here,? Thanks Timo.
>
>
> []s,
>
> Raphael Costa
>
>
>
>
>

Raphael Bittencourt S. Costa wrote:
> Ehlo all,
>
> I've been working on a migration of about 240K users from one server
> with qmail, courier imap, maildrop and ldap to postfix, dovecot, lda
> +sieve. Before the migration the server and the storage were always on
> high load. 
>
>   
It almost doesn't seem enough of a drop...! Have you benchmarked the 
various apps a little?  Postfix syncs disks like crazy to prevent mail 
loss in case of disaster - can I assume you have given some thought to 
tuning your file system which handles the spool files?

Good luck

Ed W