[libvirt-users] cgroups inside LXC containers losts memory limits after some time

[mxs kolo]

HI all

>After unpredictable time passed (1-5 day ?), cgroups inside LXC
>magicaly removed.

virsh dumpxml config look like this:
<domain type='lxc' id='3566'>
  <name>puppet</name>
  <uuid>6d49b280-5686-4e3c-b048-1b5d362fb137</uuid>
  <memory unit='KiB'>8388608</memory>
  <currentMemory unit='KiB'>8388608</currentMemory>
  <memtune>
    <hard_limit unit='KiB'>8388608</hard_limit>
    <soft_limit unit='KiB'>8388608</soft_limit>
    <swap_hard_limit unit='KiB'>9437184</swap_hard_limit>
  </memtune>
  <vcpu placement='static'>2</vcpu>
  <resource>
    <partition>/machine</partition>
  </resource>
  <os>
    <type arch='x86_64'>exe</type>
    <init>/sbin/init</init>
  </os>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/libexec/libvirt_lxc</emulator>
    <filesystem type='block' accessmode='passthrough'>
      <source dev='/dev/data/puppet'/>
      <target dir='/'/>
    </filesystem>
    <interface type='direct'>
      <mac address='02:00:00:25:a7:56'/>
      <source dev='br502' mode='bridge'/>
      <model type='virtio'/>
    </interface>
    <console type='pty' tty='/dev/pts/1'>
      <source path='/dev/pts/1'/>
      <target type='lxc' port='0'/>
      <alias name='console0'/>
    </console>
  </devices>
  <seclabel type='none'/>
</domain>

Problem go away after restart LXC container. But occurred again after
some time passed.
  For containers with broken cgroups virsh memtune fails with error:
[root@]# virsh memtune --hard-limit 8G puppet    --live --config
error: Unable to change memory parameters
error: unable to set memory hard_limit tunable: Operation not permitted

b.r.
 Maxim Kozin