[CentOS] memory cgroup max_usage_in_bytes question

Wed Apr 4 21:20:17 UTC 2018
m.roth at 5-cent.us <m.roth at 5-cent.us>

Stijn De Weirdt wrote:
> hi all,
>
> can someone help explaining what we are seeing? it makes no sense to us.
> this is a host running centos 7.4 with 3.10.0-693.17.1 kernel, and it
> has 192GB of ram
>
>> [] free -b
>>               total        used        free      shared  buff/cache
>> available
>> Mem:    201402642432 14413479936 75642777600    48586752 111346384896
>> 185689632768
>> Swap:   21474832384    31961088 21442871296
>> [] cat /sys/fs/cgroup/memory/memory.max_usage_in_bytes
>> 273102151680
>
> how can the max be so much higher than total, and this is not even memsw?
>
> either we're very tired and are overlooking something obvious, or
> there's something new to be learned ;)
>
Wonder if it's overcommitting memory.VMs do that, as a matter of course.

      mark