Dovecot: lda: fatal: internal error occured

[Mathias_Niehaus]

Hello,

a few days ago, i activated about 100 (sieve)filters in roundcube to filter our emails in folders.
Occasionally we get this every 10-45min the entry in the log files:

/var/log/mail.err

Apr 16 11:29:12 xxxx dovecot: lda: Error: userdb lookup: connect(/var/run/dovecot/auth-userdb) failed: Connection refused
Apr 16 11:29:12 xxxx dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.
Apr 16 11:29:12 xxxx dovecot: lda: Error: userdb lookup: connect(/var/run/dovecot/auth-userdb) failed: Connection refused
Apr 16 11:29:12 xxxx dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.

Then no IMAP connection is possible until a restart of the dovecot service.

We are using Plesk 12.0.18 on a Ubuntu 12.04.5 LTS Server
The mail folder is around 87G big filled with several mail accounts (1 big account consuming 74G)

I tried a few things, but i don't have anything left for trying.
Problem known or anyone having a hint to resolve that?
Thanks in advance!

 

[IgorG]

This error occurrs because the socket file /var/run/dovecot/auth-userdb isn't present. This happened because Dovecot was abruptly ended during the operation. I suggest you check corresponding Postfix errors in maillog.

 

[Mathias_Niehaus]

You are right.

/var/log/maillog

Apr 16 15:05:19 xxxx dovecot: master: Warning: service(imap-login): process_limit (100) reached, client connection are being dropped

Then the server shuts down and keeps beeing stopped.

/etc/dovecot/conf.d/
92-plesk-service-imap.conf
92-plesk-service-pop.conf
Both files keeps the entry: process_limit = 2048
but:

root@xxx:/etc# doveconf -d | grep default_ | grep _limit
default_client_limit = 1000
default_process_limit = 100
default_vsz_limit = 256 M

Any hint how to disable the default config from dovecot to get higher?

 

[Mathias_Niehaus]

Found out that "just" to set the default_process_limit = xxx and default_client_limit = xxxx with my own numbers. I needed to set the client_limit because i got an error message if i setted just the process_limit alone.
I wrote down that lines in the /etc/dovecot/conf.d/10-master.conf
Is it safe to do that or does it get deleted after a server reboot?