Use cases

Reporting on Disk Space Consumption

The disk space used is permanently monitored for each IBM SVC-Storwize storage pool:

• The Subscribed Capacity attribute of the IBM SVC-Storwize Storage Pool Monitor represents the amount of disk space that has been made available to the subscriber hosts, or in other words, the amount of disk space that is seen by the servers connected to the IBM SVC-Storwize System.

• The Consumed Capacity attribute of the IBM SVC-Storwize Storage Pool Monitor represents the actual space usage in the pool. For “thin” pools (when thin provisioning is enabled on the IBM SVC-Storwize System), this value is normally lower than the Subscribed Capacity, as it is the main purpose of thin provisioning. For traditional pools, the Consumed Capacity attribute has the same value as the Subscribed Capacity attribute, as the entirety of the subscribed disk space is fully allocated in the storage pool.

• The Consumed Capacity Percentage attribute is the most critical one as a pool usage nearing 100% means that SAN administrators will not be able to create new LUNs. By default, an alarm is triggered if the value of this parameter exceeds 75%.

Reclaiming Space of Unused Volumes

Diagnosing SAN/Network Contention

The IBM SAN Volume Controller can be considered as a storage proxy. As such, it concentrates the storage activity from many hosts and many back-end systems. Therefore, its network and fiber connectivity and performance needs to be optimal at all times. The IBM SVC-Storwize KM monitors both the iSCSI and fiber ports for the connectivity and the traffic. For the fiber ports, additional information is provided to identify the origin and/or destination of the traffic (internal, other cluster, hosts or storage systems). This allows SAN administrators to precisely understand the cause of any SAN or network contention.

To diagnose SAN/Network contention, generate activity reports:

1. Edit your IBM SVC-Storwize 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 IBM SVC-Storwize 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
5. Click OK
6. Click Save.
7. Go to %PATROL_HOME%\log and open the SEN_SVCSTORWIZE_activity_SEN_SVCSTORWIZE_FCPORT log file.

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 IBM SVC-Storwize 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 disk array, you can use the Read Byte Rate and Write Byte Rate parameters of the IBM SVC-Storwize 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, IBM SVC-Storwize 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

IBM SVC-Storwize 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 IBM SVC-Storwize 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 IBM SVC-Storwize 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 Activity: Reports on Transfer, Read and Write Bytes for all monitored storage systems
• Nodes Activity: Reports on Transfer, Read and Write Bytes for all monitored nodes
• Array Disks Activity: Reports on Transfer, Read and Write Bytes for all monitored array disks
• Fiber Ports Activity:Reports on Transfer, Sent and Received Bytes for all monitored fiber ports
• Managed Disks Activity: Reports on Transfer, Read and Write Bytes for all monitored managed disks
• Storage Pools Activity: Reports on Transfer, Read and Write Bytes on for all monitored
• Volumes Activity: Reports on Transfer, Sent and Received Bytes for all monitored volumes

1. Click OK
2. 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.