:original_name: ALM-12180.html

.. _ALM-12180:

ALM-12180 Suspended Disk I/O
============================

Description
-----------

-  For HDDs, the alarm is triggered when any of the following conditions is met:

   -  The system collects data every 3 seconds, and detects that the **svctm** value exceeds 6s for 10 consecutive periods within 30 seconds.
   -  The system collects data every 3 seconds, and detects that the **avgqu-sz** value is greater than 0, the IOPS or bandwidth is 0, and the **ioutil** value is greater than **99%** for 10 consecutive periods within 30 seconds.

-  For SSDs, the alarm is triggered when any of the following conditions is met:

   -  The system collects data every 3 seconds, and detects that the **svctm** value exceeds 3s for 10 consecutive periods within 30 seconds.
   -  The system collects data every 3 seconds, and detects that the **avgqu-sz** value is greater than 0, the IOPS or bandwidth is 0, and the **ioutil** value is greater than **99%** for 10 consecutive periods within 30 seconds.

This alarm is automatically cleared when the preceding conditions have not been met for 90s.

.. note::

   -  Run the following command in the OS to collect data:

      **iostat -x -t 1 1**

      |image1|

      Parameters are as follows:

      -  **avgqu-sz** indicates the disk queue depth.
      -  The sum of **r/s** and **w/s** is the IOPS.
      -  The sum of **rkB/s** and **wkB/s** is the bandwidth.
      -  **%util** is the **ioutil** value.

   -  The formula for calculating **svctm** is as follows:

      svctm = (tot_ticks_new - tot_ticks_old) / (rd_ios_new + wr_ios_new - rd_ios_old - wr_ios_old)

      If **rd_ios_new + wr_ios_new - rd_ios_old - wr_ios_old** is **0**, then **svctm** is **0**.

      The parameters can be obtained as follows:

      The system runs the **cat /proc/diskstats** command every 3 seconds to collect data. For example:

      |image2|

      In these two commands:

      In the data collected for the first time, the number in the fourth column is the **rd_ios_old** value, the number in the eighth column is the **wr_ios_old** value, and the number in the thirteenth column is the **tot_ticks_old** value.

      In the data collected for the second time, the number in the fourth column is the **rd_ios_new** value, the number in the eighth column is the **wr_ios_new** value, and the number in the thirteenth column is the **tot_ticks_new** value.

      In this case, the value of **svctm** is as follows:

      (19571460 - 19569526) / (1101553 + 28747977 - 1101553 - 28744856) = 0.6197

Attribute
---------

======== ============== ==========
Alarm ID Alarm Severity Auto Clear
======== ============== ==========
12180    Major          Yes
======== ============== ==========

Parameters
----------

+-------------+-------------------------------------------------------------------+
| Name        | Meaning                                                           |
+=============+===================================================================+
| Source      | Specifies the cluster or system for which the alarm is generated. |
+-------------+-------------------------------------------------------------------+
| ServiceName | Specifies the service for which the alarm is generated.           |
+-------------+-------------------------------------------------------------------+
| RoleName    | Specifies the role for which the alarm is generated.              |
+-------------+-------------------------------------------------------------------+
| HostName    | Specifies the host for which the alarm is generated.              |
+-------------+-------------------------------------------------------------------+
| DiskName    | Specifies the disk for which the alarm is generated.              |
+-------------+-------------------------------------------------------------------+

Impact on the System
--------------------

A continuously high I/O usage may adversely affect service operations and result in service loss.

Possible Causes
---------------

The disk is aged.

Procedure
---------

**Replace the disk.**

#. Log in to FusionInsight Manager and choose **O&M** > **Alarm** > **Alarms**.
#. View the detailed information about the alarm. Check the values of **HostName** and **DiskName** in the location information to obtain the information about the faulty disk for which the alarm is reported.
#. Replace the hard disk.
#. Check whether the alarm is cleared.

   -  If yes, no further action is required.
   -  If no, go to :ref:`5 <alm-12180__li1050815217817>`.

**Collect fault information.**

5. .. _alm-12180__li1050815217817:

   On FusionInsight Manager, choose **O&M**. In the navigation pane on the left, choose **Log** > **Download**.

6. Select **OMS** for **Service** and click **OK**.

7. Click |image3| in the upper right corner, and set **Start Date** and **End Date** for log collection to 10 minutes ahead of and after the alarm generation time, respectively. Then, click **Download**.

8. Contact O&M personnel and provide the collected logs.

Alarm Clearing
--------------

This alarm is automatically cleared after the fault is rectified.

Related Information
-------------------

None

.. |image1| image:: /_static/images/en-us_image_0000001375901064.png
.. |image2| image:: /_static/images/en-us_image_0000001426500589.png
.. |image3| image:: /_static/images/en-us_image_0000001405224197.png
