Use cases

Reporting on Disk Space Consumption

The Pure Storage System Monitor reports various metrics regarding the disk space in the storage system:

• The total subscribed capacity, i.e. the total amount of disk space exposed to the servers with the Subscribed Capacity attribute
• The total amount of free disk space with the Available Capacity attribute.

Detecting Oversubscription Situations (Thin Provisioning)

We call an oversubscription situation when:

• The storage system is configured for thin provisioning (“thin storage system")
• The storage system is oversubscribed, i.e. the total disk space visible to the hosts (subscribers) is greater than its actual capacity (this situation is normal for a thin pool since it is its very purpose)
• The storage pool actual consumed capacity is higher than 75%.

Such situation is highly critical because the inability to allocate additional space to a LUN when requested by the subscriber host will lead to catastrophic data loss and corruption.

The Oversubscription Situation attribute will alert you to an oversubscription situation by triggering an alarm. When such an alarm is issued by the KM, it is highly recommended that the SAN administrators add capacity as soon as possible.

Reclaiming Space of Unused Volumes

Diagnosing Slow Volumes

When servers are experiencing slow I/Os performance, you may want to verify the actual response time of the volumes the server is relying on. The response time represents the average time it takes to complete the read/write operations on a volume during the collection interval. Typically, the average response time is below 10 milliseconds. You may also want to compare this value with other volumes response time to find out if they have relatively similar throughput or if one server is really getting worse I/O performance than another.

The industry common guidelines in terms of response time are:

To identify slow volumes, you will need to create a simple dashboard. Dashboards allow you to gather specific types of data and display them in a consolidated graphical format. For detailed information about dashboards options and features, refer to the BMC documentation.

To diagnose slow volumes:

1. Log on to the TrueSight console
2. Select Dashboards from the navigation pane
3. In the Dashboards page, click Add Dashboard or select Add Dashboard from the dashboard action menu
4. Enter a Title for your dashboard and configure a Global Filter, if needed
5. Click Add Dashlet to open the dashlet library for the first column of the row
6. From the dashlet library, select the Device Performance template, and then click Close

   

7. Select Configure Dashlet by clicking the button

   

8. In the panel of input fields and options that opens below the dashboard, enter a Title for the dashlet and specify a Refresh Rate (default is 5 minutes)

9. Select the Pure Storage device for which you need to compare volumes response times

   

10. Select the Response Time parameter for the first volume, and click Apply

    

11. Repeat this operation in the next columns of the dashboard for other volumes and click Save

12. The dashboard is completed and shows the Response Time for all the selected volumes

    

If the response time is high, you will need to check the amount of data that is written and read on this volume. The bad performance may simply be due to an abnormally large amount of data to process.

Identifying Busiest Volumes

To identify the volumes that generate the most traffic on the storage system, you can use the Read Byte Rate and Write Byte Rate parameters of the Pure Storage Volume Monitor.

1. Log on to the TrueSight console
2. Select Dashboards from the navigation pane
3. In the Dashboards page, click Add Dashboard or select Add Dashboard from the dashboard action menu
4. Enter a Title for your dashboard and configure a Global Filter, if needed
5. Click Add Dashlet to open the dashlet library for the first column of the row
6. From the dashlet library, select the Monitors - Performance Overview template, and then click Close

   

7. Select Configure Dashlet by clicking the button

   

8. From the Focus list, select Multimetric comparison

9. Select the Monitor Type for which you want to create a graph. In our example, Pure Storage Volume

   

10. Select the Volumes Monitors to be displayed in the graph and click Done

11. For each selected volume, check the Read Byte Rate and Write Byte Rate parameters and click Apply

    

12. Click Save.

13. The dashboard is completed and shows the busiest volumes.

    

Generating Activity Reports

Pure Storage KM for PATROL can automatically produce text reports that provide detailed and valuable information about your monitored storage systems.

To schedule the generation of activity reports:

1. Edit your Pure Storage monitoring policy:

   

   • Log on to the TrueSight console.
   • In the navigation pane, expand Configuration and select Infrastructure Policies.
   • In the Infrastructure Policies page, locate the monitoring policy you wish to modify, click its action button and click Edit.
   • In the Edit Monitoring Policy page, locate the Pure Storage Configuration you wish to modify and click its action button to access the monitoring options panel.

2. Locate the Reporting section:

   

3. In the Schedule section, indicate the time at which the report(s) must be generated

4. Check the Activity report type to automatically generate the following reports:
   • Storage Systems: Reports on Transfer, Read and Writes Bytes for all monitored storage systems
   • Volumes: Reports on Transfer, Read and Writes Bytes for all monitored volumes

5. Click OK

6. Click Save.

The generated file(s) are time-stamped and stored in %PATROL_HOME%\log for the specific time set through the History Retention Period parameter.