vsz_limit is 18,447 PB

[Dan Langille]

On Sep 15, 2014, at 10:20 AM, Dan Langille <dan at langille.org> wrote:

> 
> On Sep 8, 2014, at 6:38 PM, Jiri Bourek <bourek at thinline.cz> wrote:
> 
>>>> 
>>>>> Background: I’m in the only user on this system, but this server is accessed by my phone, my laptop, my tablet, and perhaps a web interface.
>>>>> 
>>>> 
>>>>> 
>>>>> But there are some interesting values when I look at the output of doveconf.  Specifically, vsz_limit is 18,447 PB… yeah, that’s pretty big.
>>>>> 
>>>>> service imap-login {
>>>>> vsz_limit = 18446744073709551615 B
>>>>> }
>>>>> 
>>>> 
>>>> According to your log it was process “im ap" what ran out of memory. You are showing configuration for imap-login - they are not the same thing, see http://wiki2.dovecot.org/Design/Processes
>>> 
>>> My errror, sorry.  OK, here’s imap:
>>> 
>>> service imap {
>>>  chroot =
>>>  client_limit = 1
>>>  drop_priv_before_exec = no
>>>  executable = imap
>>>  extra_groups =
>>>  group =
>>>  idle_kill = 0
>>>  privileged_group =
>>>  process_limit = 1024
>>>  process_min_avail = 0
>>>  protocol = imap
>>>  service_count = 1
>>>  type =
>>>  unix_listener login/imap {
>>>    group =
>>>    mode = 0666
>>>    user =
>>>  }
>>>  user =
>>>  vsz_limit = 18446744073709551615 B
>>> }
>>> 
>>> Still the same value…  why not 265MB?
>> 
>> Hm, I can only guess (someone with more knowledge of dovecot source code probably knows better), but it seems like that value is magic number for "not set". My doveconf outputs the same thing on services which don't have vsz_limit set explicitly, but when I list /proc/[pid]/limits on such a service, the row called "Max address space" (which is - AFAIK - limit on vsz) shows 2GB, a value of default_vsz_limit setting.
>> 
>> I'd say don't overthink it, just put explicit vsz_limit = 512M into service imap section (if your machine's RAM allows) and be done with it.
> 
> For the record, the error has recurred a few times, so after today’s incident, I added this to dovecot.conf, and restarted dovecot:
> 
> service imap {
>  vsz_limit = 512MB
> }
> 
> FWIW, the server contains 8192 MB of RAM.

For the record, the problem has not recurred.

— 
Dan Langille

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 333 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://dovecot.org/pipermail/dovecot/attachments/20140924/1c1ca699/attachment.sig>