Docker like solutions for OpenVZ containers

It appears that this is an open issue and is this is specific to Ubuntu containers and apparmor.

A workaround was posted in there from bprodoehl:

• Start the container as privileged with --privileged
• Add the following line to the dockerfile: RUN mv /sbin/dhclient /usr/sbin/dhclient
• Run dhclient eth0 and you will still see the error message: mv: cannot move '/etc/resolv.conf.dhclient-new.29' to '/etc/resolv.conf': Device or resource busy, but you will now have an IP and you can use the network.

It seems you have somehow made an incomplete config file for CT 101, namely /etc/vz/conf/101.conf. If you're confident you have nothing important in CT 101, you can just destroy it (or manually remove /etc/vz/conf/101.conf) then try again creating CT 101.

vzctl destroy 101
vzctl create 101 --ostemplate centos-6-x86

And I must correct several misunderstandings in the site you cite.

• You don't have to download template files by yourself. Recent vzctl create will automatically download it on behalf of you. You can specify your nearest mirror site in /etc/vz/download.conf. See vztmpl-dl manpage for details.
• You don't have to unpack tar+gz template files. Just put as it is in /srv/vz/template/cache/ when you've bothered to download one.

• You should always use vzctl set CTID --save to configure CT rather than directly edit its config file:

  vzctl set 101 --save --ram 256M --swap 512M --diskspace 2G:2.2G
  

  Especially regarding diskspace, any changes in a config file won't be reflected in the ploop layout.