Backups

The backup command is used to backup the current installation.

The basic syntax of the backup command is as follows:

exordos backup -d /path/to/backup/directory

This will backup the current installation to the specified directory. The command will create a subdirectory for each domain and copy its disks to the specified directory. The backup will repeat every 24 hours by default.

To configure period of backup, run the following command:

exordos backup -d /path/to/backup/directory -p 1h

To do a backup once and exit:

exordos backup -d /path/to/backup/directory -oneshot

Basic Backup

Run backup periodically of all libvirt domains and store it in the current directory:

exordos backup

Backup Specific Domain

Run backup periodically of a specific libvirt domain and store it in the current directory:

exordos backup -n domain-name

Exclude Specific Domains

Use --exclude-name (or --no) to skip specific domains or patterns. --name and --exclude-name/--no cannot be used together.

exordos backup --exclude-name domain-foo --exclude-name domain-bar --exclude-name "domain-stand-*"

Custom Periodic Backup

Run backup periodically of all libvirt domains and store it in the current directory:

exordos backup -p 1h

Available periods are: 1m, 5m, 15m, 30m, 1h, 3h, 6h, 12h, 1d, 3d, 7d

OneShot Backup

Run backup of all libvirt domains once and store it in the current directory:

exordos backup -oneshot

Compressed Backup

Run backup of all libvirt domains and store a compressed archive in the current directory:

exordos backup --compress

Encrypted Backup

Run backup of all libvirt domains and store an encrypted archive in the current directory.

NOTE: Works only with the --compress flag.

Set the environment variables GEN_DEV_BACKUP_KEY and GEN_DEV_BACKUP_IV to encrypt the backup. The key and IV must be greater or equal to 6 bytes and less or equal to 16 bytes.

export GEN_DEV_BACKUP_KEY=secret_key
export GEN_DEV_BACKUP_IV=secret_iv

exordos backup --compress --encrypt

For decryption, use the exordos backup-decrypt command:

exordos backup-decrypt backup.tar.gz.encrypted

Restore backups

Let's consider a couple of scenarios to restore a particular machine from the backup. The backup can be as an entcrypted archive, archive or a directory. So the first step is to convert the backup to a directory:

Optional decryption of the backup

genesis backup-decrypt backup.tar.gz.encrypted

Optional decompression of the backup

tar -xzf backup.tar.gz

The backup directory can consist several subdirectories for each domain. Let's consider the following example:

.
├── a4cb5e6e-domain-foo
│   └── domain.xml
│   └── f5e1a096-1093-4d80-a21b-d453281360d5_a4cb5e6e-1ef0-450b-b28c-9638fe6e7eb9.qcow2
├── 444b5183-domain-bar
│   └── domain.xml
│   └── 005ff0d3-3945-46d0-8704-27c645dfe3ab_444b5183-a049-4415-86c2-c3c8262c1403.qcow2

• domain.xml is the domain configuration file
• *.qcow2 is the disk image

The most frequent use case is to restore a specific domain from the backup. Let's consider we already have a running domain foo but with corrupted disk and want to restore it from the backup. We can use the following commands:

# Shut down the domain
virsh shutdown foo

# Determine current disk path
sudo virsh domblklist foo

# Replace the disk
cp backup/a4cb5e6e-domain-foo/f5e1a096-1093-4d80-a21b-d453281360d5_a4cb5e6e-1ef0-450b-b28c-9638fe6e7eb9.qcow2 /var/lib/libvirt/images/foo.qcow2

# Start the domain
virsh start foo

Rotation

For the periodic backup, you can set the number of backups to keep (rotation number). The default value is 5. Use the --rotate option:

exordos backup --rotate 10

Prevent disk overflow

Backups can take a lot of disk space and it can be a reason to crash the whole system if a disk will be full. To prevent such a situation you can set a threshold for disk space that should be free. If during a backup process this threshold will be reached, the backup process will stop. Use the --min-free-space option to set the threshold in GB.

exordos backup --min-free-space 50