[lxc-users] udevadm trigger corrupts the container

[Christoph Mathys]

On Mon, Aug 3, 2015 at 5:09 PM, Christoph Mathys <eraserix at gmail.com> wrote:
> I'll try to reproduce it tomorrow and provide a small script.

I've been struggling to reproduce this again on anything but a full
PREEMPT_RT_FULL kernel (lxc 1.0.7, Trusty). As guests in the container
I tried Debian Jessie and Ubuntu Precise.
- For Ubuntu Precise, the error occurs very quick when using
lxc.autodev on a preempt rt kernel. I have not seen it on an ubuntu or
a mainline kernel during my last test runs.
- For Debian Jessie, the error did not occur at all (lxc.autodev is
the default).

So it seems that when using the default settings for lxc for the
respective distributions, one should be fine.

Below the script I used for testing. On my preempt rt kernels and
using a ubuntu precise, this usually fails on the very first
invocation with:
start: Job failed to start

--------------- script start ----------------
set -o errexit
set -o nounset

# 0 use debian jessie inside the container
# 1 use ubuntu precise inside the container
use_ubuntu=1
cont=tmpdev
sudo lxc-destroy -n $cont -f || true

if [ $use_ubuntu -eq 0 ] ; then
    sudo lxc-create -n $cont -t debian -- -r jessie
else
    sudo lxc-create -n $cont -t ubuntu -- -r precise
    echo "lxc.autodev = 1" | \
        sudo tee -a /var/lib/lxc/$cont/config > /dev/null
fi

echo starting test
testcount=0
while true; do
    sudo lxc-start -n $cont -d
    sudo lxc-wait -n $cont -s'RUNNING'
    sudo udevadm trigger --action=change
    sudo lxc-attach -n $cont --clear-env -- /etc/init.d/procps restart
    sudo lxc-stop -n $cont
    testcount=$((testcount + 1))
    echo "completed test $testcount"
    sleep 0.5
done