Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide

Using the performance modeling tool

The SSD Cache Performance Modeling tool helps you determine the performance improvement for SSD cache capacity when you run the performance modeling tool with a workload that has the same characteristics as what you run in production. The tool provides an estimate of performance using the following metrics: cache hit percentage and average response time. This tool shows actual performance for the physical SSD cache that you created.

1. In the AMW, select the Storage & Copy Services tab.
2. To access the performance modeling tool, highlight the SSD Cache node in the logical tree view.
3. Do one of the following:
   • From the menu bar, select Storage > SSD Cache > Run Performance Modeling.
   • Right click on the SSD cache and select Run Performance Modeling.
   The SSD Cache Performance Modeling window is displayed.
4. Review the information in the Modeling Information area of the SSD Cache Performance Modeling window.
5. Select one of the following options from View results to choose the format you want to view the results:
   • Response Time
   • Cache Hit %
6. Click Start to run the performance modeling tool.
   NOTE: Depending on the cache capacity and workload, it may take about 10 to 20 hours to fully populate the cache. There is valid information even after a run of a few minutes, but it takes a number of hours to obtain the most accurate predictions.

   NOTE: While the performance modeling tool is running, a progress bar is displayed in the main area of the window. You can close or minimize the window and the performance modeling continues to run. You can even close the MD Storage Manager and the performance modeling session continues to run.

   NOTE: At the beginning of the ramp up time, the performance may be slower than if SSD cache was never enabled.
7. To save the results of a performance modeling session, click Save As and save the data to a .csv file.