[Dovecot] Delay email!

[Timo Sirainen]

On Thu, 2010-12-09 at 17:15 -0200, Henrique Fernandes wrote:
> I am using postfix + dovecot 2.0.6  + mailman
> 
> And others 2 serves with only postfix and dovecot writing at same storage
> with OCFS2.
> 
> We are having problens with IOwait, and still trying to figure out why that
> is happen!

sdbox/mdbox format should reduce disk IO compared to maildir.

> But, problem becomes much worse when some emails are used in mailman, when
> it happens all 3 serves became really slow. iowait goes to 80.
> 
> Does anyone have an idea how to slow down the dovecot lda ?

By telling Postfix to limit the number of simultaneous dovecot-lda
processes. In master.cf you have:

# service type  private unpriv  chroot  wakeup  maxproc command + args

So change the dovecot-lda entry's maxproc from "-" to however many
simultaneous dovecot-ldas you want.