How to Change Container ID in OpenVZ

OpenVZ is a virtualization technology for Linux. In OpenVZ containers also known as Virtual Machine or VPS. Containers share the resources of the physical machine. Means a particular amount of Disk space and RAM will not be allocated to any particular VPS (Container). Resources pool equally shared by all Containers on demand.

In this article I will show how you can change the ID of an OpenVZ container.

Method #1 : Create Checkpoint and Rename Container ID

Use a checkpoint and rename the container directories on the shell, In this tutorial I am going to change ID of a container from 101 to 102.

Creating Checkpoint of The VM

# vzctl chkpnt 101 --dumpfile /tmp/ovz-101.dump

Rename The Files of the Container

# mv /etc/vz/conf/101.conf /etc/vz/conf/102.conf
# mv /vz/private/101 /vz/private/102
# mv /vz/root/101 /vz/root/102

Restore Checkpoint

Finally restore the checkpoint using below command.

# vzctl restore 102 --dumpfile /tmp/ovz-101.dump

Method #2 : Using vzdump Command

Alternatively you use the vzdump command to create a backup and restore it with vzrestore command under new container ID.

# mkdir /home/backup
# chmod 700 /home/backup
# chown root:root /home/backup

Container Backup

Now backup the container with ID 101.

# vzdump --compress --dumpdir /home/backup 101

Restore Backup

Now restore the container with ID 102.

# vzrestore /home/backup/vzdump-101.tgz 102

Now shutdown container 101 and start 102 using below command.

# vzctl stop 101
# vzctl start 102

Test your container 102 is fully working if everything looks file then delete container 101.

# vzctl destroy 101