.. _Monitoring Physical Disks:

Monitoring Physical Disks
-------------------------

The S.M.A.R.T. status of physical disks is monitored by the ``smartctl`` tool installed along with |product_name|. The tool is run every 10 minutes as a ``cron`` job also added during installation. The ``smartctl`` tool polls all physical disks attached to nodes in the cluster, including caching and journaling SSDs, and reports the results to the MDS server.

.. note:: For the tool to work, enable the S.M.A.R.T. functionality in node's BIOS.

You can view disk poll results for the last 10 minutes in the output of the ``vstorage top`` command. For example:

.. image:: /images/image027.png
   :align: center
   :class: align-center

If the **SMART warning** message is shown in the main table, one of the physical disks is in pre-failure condition according to S.M.A.R.T. Press **d** to switch to the disks table to see more details. For example:

.. image:: /images/image028.png
   :align: center
   :class: align-center

The disks table shows the following parameters:

+-------------+------------------------------------------------------------------------------------------+
| Parameter   | Description                                                                              |
+=============+==========================================================================================+
| DISK        | Disk name assigned by operating system.                                                  |
+-------------+------------------------------------------------------------------------------------------+
| SMART       | Disk's S.M.A.R.T. status:                                                                |
|             |                                                                                          |
|             | -  OK: The disk is healthy.                                                              |
|             |                                                                                          |
|             | -  Warn: The disk is in pre-failure condition.                                           |
|             |                                                                                          |
|             | Pre-failure condition means that at least one of these S.M.A.R.T. counters is nonzero:   |
|             |                                                                                          |
|             | -  Reallocated Sector Count                                                              |
|             |                                                                                          |
|             | -  Reallocated Event Count                                                               |
|             |                                                                                          |
|             | -  Current Pending Sector Count                                                          |
|             |                                                                                          |
|             | -  Offline Uncorrectable                                                                 |
+-------------+------------------------------------------------------------------------------------------+
| TEMP        | Disk temperature in Celsius.                                                             |
+-------------+------------------------------------------------------------------------------------------+
| CAPACITY    | Disk capacity.                                                                           |
+-------------+------------------------------------------------------------------------------------------+
| SERIAL      | Disk serial number.                                                                      |
+-------------+------------------------------------------------------------------------------------------+
| MODEL       | Disk model.                                                                              |
+-------------+------------------------------------------------------------------------------------------+
| HOST        | Disk's host address.                                                                     |
+-------------+------------------------------------------------------------------------------------------+

.. note:: To disable S.M.A.R.T. disk monitoring, delete the corresponding ``cron`` job.