.. _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|. For it to work, S.M.A.R.T. functionality must be enabled in node's BIOS. 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.

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:

.. raw:: latex

   \setlist[description]{leftmargin=!,labelindent=0pt,labelwidth=1em+\widthof{CAPACITY}}

**DISK**
   Disk name assigned by operating system.

**SMART**
   Disk's S.M.A.R.T. status:

   .. raw:: latex

      \setlist[description]{leftmargin=!,labelindent=0pt,labelwidth=1em+\widthof{Warn}}

   **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.

.. raw:: latex

   \setlist[description]{leftmargin=!,labelindent=0pt,labelwidth=1em+\widthof{ }}

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