mmap failed messages in syslog

[Aki Tuomi]

> On 10 May 2018 at 07:52 Shawn Heisey <elyograg at elyograg.org> wrote:
> 
> 
> On 5/9/2018 10:15 PM, Shawn Heisey wrote:
> > It's been about three weeks since I asked this question.  All the 
> > information I have available says that all users have no limits on 
> > virtual memory, so it must be dovecot itself that sets the limit.  Can 
> > that be changed in the 1.2 version?  I can't upgrade to 2.x yet.
> >
> > Here's an actual syslog entry, redacted to remove identifying info:
> >
> > May 9 21:55:48 frodo dovecot: IMAP(REDACTED1): mmap() failed with 
> > index cache file /home/vmail/REDACTED2/dovecot.index.cache: Cannot 
> > allocate memory
> >
> > The file that it could not mmap here is 189843456 bytes.
> 
> I may have figured it out.  After a little googling to see how virtual 
> memory limits are set in C programs, and then some grepping of the 
> 1.2.15 dovecot source, I saw evidence that setting the mail_process_size 
> value in dovecot.conf can increase the limit on virtual memory.  I have 
> done this, and will keep an eye on the log to see if it helps.
> 
> Thanks,
> Shawn
>

Hi Shawn, you've figured it out correctly. If you can spare the memory, you should probably up the default vsize limit to something like 1G.

Aki