Image Backup with the RHV Plugin

Bacula Enterprise Only

This solution is only available for Bacula Enterprise. For subscription inquiries, please reach out to sales@baculasystems.com.

With the image-level backup strategy, the Bacula Enterprise RHV Plugin saves the virtual machine configuration and virtual disks through the RHV platform. A Bacula File Daemon does not need to be installed in every guest virtual machine. Instead, the RHV Plugin is installed on the File Daemon that acts as the backup proxy for the RHV environment.

Installing this File Daemon on the same system as a Storage Daemon can reduce the number of times that backup data traverses the network.

The RHV Plugin communicates with the RHV environment to read and save virtual machine disks. Because it reads virtual disk images directly, Bacula does not need to traverse the guest file system and open, read, close, and inspect every file. Image-level backup can therefore use fewer guest resources than running a file-level backup inside every virtual machine.

Image-level backup reads allocated disk data without necessarily knowing its purpose inside the guest. Consequently, it may also save data that is not useful for recovery, such as swap data and temporary files. Consult the RHV Plugin documentation for supported exclusion, snapshot, and transport capabilities.

Proxy Server

The RHV Plugin runs in a virtual machine located inside the RHV environment being protected. Deploy a proxy virtual machine containing the Bacula File Daemon and the RHV Plugin.

Minimum Requirements for the Proxy Server

OS: There is no specific operating-system requirement, and proxy mode should work with any supported, up-to-date operating system. Debian 10 (Buster) is recommended because it is the platform on which proxy mode has been tested most extensively.
RAM: 2 GB.
Network: Access to the RHV logical network.
Storage: 4 GB.
Bacula Enterprise version: 12.4.0 or later.
Java Virtual Machine: Version 8.

A proxy server meeting these minimum requirements can process up to 20 backups in parallel. Provide an additional 1 GB of available RAM for every 10 additional parallel backups.

Backup Chain Considerations

When the RHV Plugin uses block-level change tracking, all backups required by the selected restore point must remain available. Restoring an Incremental chain normally requires the preceding Full backup and every subsequent Incremental backup through the desired restore point. If one of these backups is unavailable, Bacula may be unable to reconstruct a consistent virtual machine image.

Using Differential backups can reduce the number of backup jobs required for a restore, because a restore normally needs the preceding Full backup and the selected Differential backup.

Configure Volume retention periods so that the Full backup and every dependent Incremental or Differential backup remain available for the entire required recovery period. Periodically test image restores to confirm that the backup chain, virtual machine configuration, and virtual disks can be recovered.