VM Backup Fleecing
~~~~~~~~~~~~~~~~~~
-WARNING: Backup fleecing is still being worked on (also in upstream QEMU) and is
-currently only a technology preview.
-
When a backup for a VM is started, QEMU will install a "copy-before-write"
filter in its block layer. This filter ensures that upon new guest writes, old
data still needed for the backup is sent to the backup target first. The guest
'Schedule' field in the UI can be freely edited, and it contains several
examples that can be used as a starting point in its drop-down list.
-[thumbnail="screenshot/gui-cluster-backup-edit-02-retention.png"]
-
You can configure job-specific xref:vzdump_retention[retention options]
overriding those from the storage or node configuration, as well as a
xref:vzdump_notes[template for notes] for additional information to be saved
together with the backup.
-[thumbnail="screenshot/gui-cluster-backup-edit-03-template.png", float="left"]
Since scheduled backups miss their execution when the host was offline or the
pvescheduler was disabled during the scheduled time, it is possible to configure
the behaviour for catching up. By enabling the `Repeat missed` option (in the
----------------
With the `prune-backups` option you can specify which backups you want to keep
-in a flexible manner. The following retention options are available:
+in a flexible manner.
+
+[thumbnail="screenshot/gui-cluster-backup-edit-02-retention.png"]
+
+The following retention options are available:
`keep-all <boolean>` ::
Keep all backups. If this is `true`, no other options can be set.
You can add notes to backups using the 'Edit Notes' button in the UI or via the
storage content API.
+[thumbnail="screenshot/gui-cluster-backup-edit-03-template.png"]
+
It is also possible to specify a template for generating notes dynamically for
a backup job and for manual backup. The template string can contain variables,
surrounded by two curly braces, which will be replaced by the corresponding