I just had to remove any mounts of cgroup
from /etc/fstab
and I solved the problem for Devices cgroup isn't mounted
. I think that Module br_netfilter not found
is just a warning and does not prevent Docker from starting. But you can fix it by installing:
apt-get install linux-image-3.19.0-33-generic linux-image-extra-3.19.0-33-generic
After that you have to reboot.
The "extra" is needed because aufs is not anymore included with basic image in Ubuntu.