Backup Storage
==============

.. _storage_disk_management:

Disk Management
---------------

.. image:: images/screenshots/pbs-gui-disks.png
  :align: right
  :alt: List of disks

Proxmox Backup Server comes with a set of disk utilities, which are
accessed using the ``disk`` subcommand or the web interface. This subcommand
allows you to initialize disks, create various filesystems, and get information
about the disks.

.. image:: images/screenshots/pbs-gui-disks.png
  :align: right
  :alt: Web Interface Administration: Disks

To view the disks connected to the system, navigate to **Administration ->
Storage/Disks** in the web interface or use the ``list`` subcommand of
``disk``:

.. code-block:: console

  # proxmox-backup-manager disk list
  ┌──────┬────────┬─────┬───────────┬─────────────┬───────────────┬─────────┬────────┐
  │ name │ used   │ gpt │ disk-type │        size │ model         │ wearout │ status │
  ╞══════╪════════╪═════╪═══════════╪═════════════╪═══════════════╪═════════╪════════╡
  │ sda  │ lvm    │   1 │ hdd       │ 34359738368 │ QEMU_HARDDISK │       - │ passed │
  ├──────┼────────┼─────┼───────────┼─────────────┼───────────────┼─────────┼────────┤
  │ sdb  │ unused │   1 │ hdd       │ 68719476736 │ QEMU_HARDDISK │       - │ passed │
  ├──────┼────────┼─────┼───────────┼─────────────┼───────────────┼─────────┼────────┤
  │ sdc  │ unused │   1 │ hdd       │ 68719476736 │ QEMU_HARDDISK │       - │ passed │
  └──────┴────────┴─────┴───────────┴─────────────┴───────────────┴─────────┴────────┘

To initialize a disk with a new GPT, use the ``initialize`` subcommand:

.. code-block:: console

  # proxmox-backup-manager disk initialize sdX

.. image:: images/screenshots/pbs-gui-disks-dir-create.png
  :align: right
  :alt: Create a directory

You can create an ``ext4`` or ``xfs`` filesystem on a disk using ``fs
create``, or by navigating to **Administration -> Storage/Disks -> Directory**
in the web interface and creating one from there. The following command creates
an ``ext4`` filesystem and passes the ``--add-datastore`` parameter, in order to
automatically create a datastore on the disk (in this case ``sdd``). This will
create a datastore at the location ``/mnt/datastore/store1``:

.. code-block:: console

  # proxmox-backup-manager disk fs create store1 --disk sdd --filesystem ext4 --add-datastore true

.. image:: images/screenshots/pbs-gui-disks-zfs-create.png
  :align: right
  :alt: Create ZFS

You can also create a ``zpool`` with various raid levels from **Administration
-> Storage/Disks -> ZFS** in the web interface, or by using ``zpool create``. The command
below creates a mirrored ``zpool`` using two disks (``sdb`` & ``sdc``) and
mounts it under ``/mnt/datastore/zpool1``:

.. code-block:: console

  # proxmox-backup-manager disk zpool create zpool1 --devices sdb,sdc --raidlevel mirror

.. note:: You can also pass the ``--add-datastore`` parameter here, to automatically
  create a datastore from the disk.

You can use ``disk fs list`` and ``disk zpool list`` to keep track of your
filesystems and zpools respectively.

Proxmox Backup Server uses the package smartmontools. This is a set of tools
used to monitor and control the S.M.A.R.T. system for local hard disks. If a
disk supports S.M.A.R.T. capability, and you have this enabled, you can
display S.M.A.R.T. attributes from the web interface or by using the command:

.. code-block:: console

  # proxmox-backup-manager disk smart-attributes sdX

.. note:: This functionality may also be accessed directly through the use of
  the ``smartctl`` command, which comes as part of the smartmontools package
  (see ``man smartctl`` for more details).


.. _datastore_intro:

:term:`Datastore`
-----------------

A datastore refers to a location at which backups are stored. The current
implementation uses a directory inside a standard Unix file system (``ext4``,
``xfs`` or ``zfs``) to store the backup data.

Datastores are identified by a simple *ID*. You can configure this
when setting up the datastore. The configuration information for datastores
is stored in the file ``/etc/proxmox-backup/datastore.cfg``.

.. note:: The `File Layout`_ requires the file system to support at least *65538*
   subdirectories per directory. That number comes from the 2\ :sup:`16`
   pre-created chunk namespace directories, and the ``.`` and ``..`` default
   directory entries. This requirement excludes certain filesystems and
   filesystem configurations from being supported for a datastore. For example,
   ``ext3`` as a whole or ``ext4`` with the ``dir_nlink`` feature manually disabled.


Datastore Configuration
~~~~~~~~~~~~~~~~~~~~~~~

.. image:: images/screenshots/pbs-gui-datastore-content.png
  :align: right
  :alt: Datastore Overview

You can configure multiple datastores. A minimum of one datastore needs to be
configured. The datastore is identified by a simple *name* and points to a
directory on the filesystem. Each datastore also has associated retention
settings of how many backup snapshots for each interval of ``hourly``,
``daily``, ``weekly``, ``monthly``, ``yearly`` as well as a time-independent
number of backups to keep in that store. :ref:`backup-pruning` and
:ref:`garbage collection <client_garbage-collection>` can also be configured to
run periodically, based on a configured schedule (see
:ref:`calendar-event-scheduling`) per datastore.


.. _storage_datastore_create:

Creating a Datastore
^^^^^^^^^^^^^^^^^^^^
.. image:: images/screenshots/pbs-gui-datastore-create-general.png
  :align: right
  :alt: Create a datastore

You can create a new datastore from the web interface, by clicking **Add
Datastore** in the side menu, under the **Datastore** section. In the setup
window:

* *Name* refers to the name of the datastore
* *Backing Path* is the path to the directory upon which you want to create the
  datastore
* *GC Schedule* refers to the time and intervals at which garbage collection
  runs
* *Prune Schedule* refers to the frequency at which pruning takes place
* *Prune Options* set the amount of backups which you would like to keep (see
  :ref:`backup-pruning`).
* *Comment* can be used to add some contextual information to the datastore.

Alternatively you can create a new datastore from the command line. The
following command creates a new datastore called ``store1`` on
:file:`/backup/disk1/store1`

.. code-block:: console

  # proxmox-backup-manager datastore create store1 /backup/disk1/store1


Managing Datastores
^^^^^^^^^^^^^^^^^^^

To list existing datastores from the command line, run:

.. code-block:: console

  # proxmox-backup-manager datastore list
  ┌────────┬──────────────────────┬─────────────────────────────┐
  │ name   │ path                 │ comment                     │
  ╞════════╪══════════════════════╪═════════════════════════════╡
  │ store1 │ /backup/disk1/store1 │ This is my default storage. │
  └────────┴──────────────────────┴─────────────────────────────┘

You can change the garbage collection and prune settings of a datastore, by
editing the datastore from the GUI or by using the ``update`` subcommand. For
example, the below command changes the garbage collection schedule using the
``update`` subcommand and prints the properties of the datastore with the
``show`` subcommand:

.. code-block:: console

  # proxmox-backup-manager datastore update store1 --gc-schedule 'Tue 04:27'
  # proxmox-backup-manager datastore show store1
  ┌────────────────┬─────────────────────────────┐
  │ Name           │ Value                       │
  ╞════════════════╪═════════════════════════════╡
  │ name           │ store1                      │
  ├────────────────┼─────────────────────────────┤
  │ path           │ /backup/disk1/store1        │
  ├────────────────┼─────────────────────────────┤
  │ comment        │ This is my default storage. │
  ├────────────────┼─────────────────────────────┤
  │ gc-schedule    │ Tue 04:27                   │
  ├────────────────┼─────────────────────────────┤
  │ keep-last      │ 7                           │
  ├────────────────┼─────────────────────────────┤
  │ prune-schedule │ daily                       │
  └────────────────┴─────────────────────────────┘

Finally, it is possible to remove the datastore configuration:

.. code-block:: console

  # proxmox-backup-manager datastore remove store1

.. note:: The above command removes only the datastore configuration. It does
   not delete any data from the underlying directory.


File Layout
^^^^^^^^^^^

After creating a datastore, the following default layout will appear:

.. code-block:: console

  # ls -arilh /backup/disk1/store1
  276493 -rw-r--r-- 1 backup backup       0 Jul  8 12:35 .lock
  276490 drwxr-x--- 1 backup backup 1064960 Jul  8 12:35 .chunks

`.lock` is an empty file used for process locking.

The `.chunks` directory contains folders, starting from `0000` and increasing in
hexadecimal values until `ffff`. These directories will store the chunked data,
categorized by checksum, after a backup operation has been executed.

.. code-block:: console

 # ls -arilh /backup/disk1/store1/.chunks
 545824 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 ffff
 545823 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fffe
 415621 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fffd
 415620 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fffc
 353187 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fffb
 344995 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fffa
 144079 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fff9
 144078 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fff8
 144077 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 fff7
 ...
 403180 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 000c
 403179 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 000b
 403177 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 000a
 402530 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0009
 402513 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0008
 402509 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0007
 276509 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0006
 276508 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0005
 276507 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0004
 276501 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0003
 276499 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0002
 276498 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0001
 276494 drwxr-x--- 2 backup backup 4.0K Jul  8 12:35 0000
 276489 drwxr-xr-x 3 backup backup 4.0K Jul  8 12:35 ..
 276490 drwxr-x--- 1 backup backup 1.1M Jul  8 12:35 .


