proxmox-backup/docs/maintenance.rst

Maintenance Tasks
=================

Pruning & Garbage Collection
----------------------------

Pruning can be scheduled on both a backup group and a datastore level. To access
pruning functionality for a specific backup group, you can use the prune command
line option discussed in :ref:`backup-pruning`, or navigate to the **Content**
tab of the datastore and click the scissors icon in the **Actions** column of
the relevant backup group. To prune on a datastore level, scheduling options can
be found under the **Prune & GC** tab of the datastore. Here you can set
retention settings and edit the interval at which pruning takes place.

.. image:: images/screenshots/pbs-gui-datastore-prunegc.png
  :align: right
  :alt: Prune and garbage collection options

You can monitor and run :ref:`garbage collection <garbage-collection>` on the
Proxmox Backup Server using the ``garbage-collection`` subcommand of
``proxmox-backup-manager``. You can use the ``start`` subcommand to manually
start garbage collection on an entire datastore and the ``status`` subcommand to
see attributes relating to the :ref:`garbage collection <garbage-collection>`.

This functionality can also be accessed in the GUI, by navigating to **Prune &
GC** from the top panel. From here, you can edit the schedule at which garbage
collection runs and manually start the operation.


.. _verification:

Verification
------------

.. image:: images/screenshots/pbs-gui-datastore-verifyjob-add.png
  :align: right
  :alt: Adding a verify job

Proxmox Backup offers various verification options to ensure that backup data is
intact.  Verification is generally carried out through the creation of verify
jobs. These are scheduled tasks that run verification at a given interval (see
:ref:`calendar-events`). With these, you can set whether already verified
snapshots are ignored, as well as set a time period, after which verified jobs
are checked again. The interface for creating verify jobs can be found under the
**Verify Jobs** tab of the datastore.

.. Note:: It is recommended that you reverify all backups at least monthly, even
  if a previous verification was successful. This is becuase physical drives
  are susceptible to damage over time, which can cause an old, working backup
  to become corrupted in a process known as `bit rot/data degradation
  <https://en.wikipedia.org/wiki/Data_degradation>`_. It is good practice to
  have a regularly recurring (hourly/daily) verification job, which checks new
  and expired backups, then another weekly/monthly job that will reverify
  everything. This way, there will be no surprises when it comes to restoring
  data.

Aside from using verify jobs, you can also run verification manually on entire
datastores, backup groups, or snapshots. To do this, navigate to the **Content**
tab of the datastore and either click *Verify All*, or select the *V.* icon from
the *Actions* column in the table.