Norweg

Hi Guys,

Since about a month I'm trying to understand what's is going on with my server.
From time to time dovecot's imap service goes into status D (uninteruptable sleep if I'm not mistaken). Usually there are several imap processes that goest into this state and CPU load goes up to 40-50, server starts to omit http/smtp/pop3 and other requests. Impossible to kill those blocking processes as they are in status D.
The only solution is to reboot (sometimes if I notice too late and whole memory is already consumed even reboot won't work. Hard power off-on in this case).

Logs are not showing anything unusual. Even with processes in status D other imap processes logging successful retrieval of login/passwords from MYSQL database.

Anyone has a clue what it can be? Where to start investigation?

Thanks in advance!