[lxc-users] sysctl -p no longer allowed in container

[Dan Kegel]

I did, but it was a slightly older version from the ppa.

Updating lxc and lxcfs to the one in trusty-backports, and then
creating a new container, seems to have helped!

$ apt-cache policy lxcfs
lxcfs:
  Installed: 0.11-0ubuntu3~ubuntu14.04.1
$ sudo lxc-create -t download -n ubu1510-x -- --dist ubuntu --release
wily --arch amd64
...
$ cat /proc/sys/kernel/sem
250 65536 32 32768
$ ssh ubu1510-x
$ cat /proc/sys/kernel/sem
250 65536 32 32768

I haven't figured out how to endow an old container with higher sem
settings yet...
diff on the config files and etc didn't immediately illuminate the
way, as the old container's a bit dirty.
But I can live with recreating them.

Let's hope I'm not just short on coffee this morning, and this really
did fix the problem :-)
- Dan

On Thu, Dec 10, 2015 at 11:09 PM, Fajar A. Nugraha <list at fajar.net> wrote:
> On Fri, Dec 11, 2015 at 12:20 PM, Dan Kegel <dank at kegel.com> wrote:
>>
>> Came back to this because it hit me again (14.04 host, 15.10 guest this
>> time).
>> I actually don't need to be able to write to /proc/sys/kernel/sem
>> from inside the container; I just need its limits to be high enough.
>>
>> $ uname -a
>> Linux dank-desktop 3.13.0-66-generic #108-Ubuntu SMP Wed Oct 7
>> 15:20:27 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
>>
>> $ apt-cache policy lxc
>> lxc:
>>   Installed: 1.1.5-0ubuntu3~ubuntu14.04.1
>>
>> Looks like at one point, inside was going to inherit from outside:
>> http://lists.linuxfoundation.org/pipermail/containers/2014-May/034544.html
>> but that doesn't seem to be happening here:
>>
>> $ cat /proc/sys/kernel/sem
>> 250 65536 32 32768
>> $ sudo lxc-start -n foo
>> $ ssh foo
>> $ cat /proc/sys/kernel/sem
>> 250 32000 32 128
>>
>
>
> Do you have lxcfs installed? At least my installation has high-enough limit
> without me having to do anything.
>
> dev ~ # cat /proc/sys/kernel/sem
> 32000   1024000000      500     32000
> dev ~ # lxc-attach -n app01 -- cat /proc/sys/kernel/sem
> 32000   1024000000      500     32000
>
> ubuntu 14.04, linux-image-generic-lts-wily 4.2.0.18.13, lxc
> 1.1.5-0ubuntu3~ubuntu14.04.1 (from backports), lxcfs
> 0.12-0ubuntu5~ubuntu14.04.1~ppa1 (from ppa).
>
> --
> Fajar
>
> _______________________________________________
> lxc-users mailing list
> lxc-users at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-users