[Dovecot] Error: file_dotlock_open() failed with file + Too many open files

Timo Sirainen tss at iki.fi
Sun Sep 22 01:46:05 EEST 2013

On 27.8.2013, at 13.56, Kavish Karkera <kavish.karkera at yahoo.com> wrote:

> We are getting these below error on our IMAP server. 
> is this because of open file limits.??

I guess it's because you have a virtual mailbox that consists of a ton of real mailboxes? Unfortunately the virtual mailboxes currently open all of the real mailboxes' index files immediately and keep them all open. This will be fixed some day in future, but for now you need enough file descriptors for them all.

> We have set it to 4096.
> [root at vish conf.d]# ulimit -n
> 4096

Dovecot's init script could have changed it. You need to look at the running dovecot process's limits to be sure:

cat /proc/`pidof dovecot`/limits | grep 'Max open files'

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