How to restore OpenVZ / Virtuozzo 7 (Disaster Recovery – DR)
Introduction
This blog explains how to restore an OpenVZ / Virtuozzo 7 node after reloading CentOS 7, using a full-node backup that stores container data inside a loopback filesystem (vz-private.ext4).
The steps below are based on a real production recovery, where multiple containers were successfully restored and brought online with minimal downtime.
1. This guide is suitable for:
2. Post-OS reload recovery
3. Disaster Recovery (DR)
4. Server rebuilds
Prerequisites
1. A freshly provisioned server with console or SSH access
2. A supported host operating system installed:
3. Root-level access
1. CentOS 7
2. VzLinux 7
3. Virtuozzo 7
4. Internet connectivity (for package installation)
5. An existing OpenVZ 7 full-node backup
6. Backup created from the same OpenVZ major version
Step 1:
Reload CentOS 7
Reinstall the operating system using your provider’s control panel.
After installation:
1. Log in as root
2. Do not create any containers
3. Do not modify /vz manually yet
Step 2:
Install the OpenVZ kernel and required user-space tools:
| $ yum install -y epel-release $ yum install -y vzkernel vzctl vzquota ploop prlctl $ reboot |
After rebooting, verify the kernel using the following command.
| $ uname -r |
Verify OpenVZ is operational:
| $ vzlist -a |
Step 3:
Prepare OpenVZ Directory Structure
Ensure the OpenVZ directory structure exists:
| $ mkdir -p /vz/{private,root,template,backup} |
Confirm /vz/private is empty:
| $ ls -A /vz/private |
If not empty, back it up and recreate it.
Step 4:
Restore the Backup Archive
Copy the full-node backup archive to the server (example location: /root) and extract it:
| $ cd /root $ tar -xvf server-backup-2026-01-01.tar.gz |
This will extract the backup into:
| $ /root/backupopenvz/ |
Verify contents:
| ls /root/backupopenv8 |
You should see:
Step 5:
Container data is stored inside a loopback ext4 filesystem.
Mount this filesystem directly to /vz/private so OpenVZ can detect containers immediately.
| $ mount -o loop /root/backupopenvz/vz-private.ext4 /vz/private/ |
Verify the mount:
| $ mount | grep vz-private |
Verify container directories:
| $ ls /vz/private |
Expected output:
⚠️ Do not add this mount to /etc/fstab.
This mount is intended only for the restore process.
Step 6:
Restore only the OpenVZ configuration directory (do not replace the full /etc):
| $ cp -a /root/backupopenvz/etc/vz /etc/ |
Verify container configs:
| $ ls /etc/vz/conf |
Expected output:
Step 7:
Restore container OS templates:
| $ cp -a /root/backupopenvz/vz/template/* /vz/template/ |
Verify:
| $ ls /vz/template |
Step 8:
Start containers one by one:
| $ vzctl start 101 $ vzctl start 102 $ vzctl start 103 $ vzctl start 104 |
Check status:
| $ vzlist -a |
Step 9:
Enter a container:
| vzctl enter 101 |
Inside the container, verify:
| $ ip a $ df -h $ ping 8.8.8.8 |
Exit and repeat for others if required.
Conclusion:
By following these steps, you can reliably restore an OpenVZ / Virtuozzo 7 node after a CentOS 7 reload.
This approach:
1. Preserves container data
2. Avoids configuration corruption
3. Minimises downtime
4. Is repeatable and production-safe
