[Dovecot] IO rate quotas?

[Timo Sirainen]

On Thu, 2011-04-07 at 16:33 +0200, Kádár Tamás (KTamas) wrote:

> However once in a while, someone goes rogue, we
> install a new version of thunderbird, someone accidentally sets up an
> email account in thunderbird mistakingly leaving the download
> everything option on. This causes high IO on our server, and a single
> user can quickly more or less kill the whole server in mere minutes,
> load average quickly spiking to 30-40-50 and everything becomes
> sloooooow (obviously).

So a single process that is reading files fast enough from disk can
cause disk IO to spike in a way that makes all other processes wait for
available disk IO? I don't think that's a common problem. Typically only
that one process would be waiting for disk IO and the load would
increase by 1 (or maybe a little bit more, but definitely not by 50)..
Maybe you should look into Linux I/O schedulers and see if you're using
the wrong one.

> Is there any way I can limit the amount of IO a certain user can use?

Not in Dovecot.