Draft Document for Review February 7, 2020 3:15 pm 8464ch11_Monitoring.fm In this example, the maximum total data transfer value is 497 MBps (MiB/s Total Xfer), but that  value is mainly driven by the premigration read task (MiB/s Fr_TVC PreMig). If premigration  causes an performance issue, review the PMPRIOR and PMTHLVL setting for tuning.  In addition to daily and monthly summary reports per cluster, VEHSTATS provides a  side-by-side comparison of all clusters for the entire measurement interval. Examine this  report for an overall view of the grid, and for significant or unexpected differences between  the clusters.  Summary reports 11.5.6 Performance evaluation tool for VEHSTATS reports After you collect the statistics data from your clusters, you can use available tools to format  and plot the binary data. For more information, see  IBM Virtualization Engine TS7700 Series Best Practices -  Understanding, Monitoring and Tuning the TS7700 Performance , WP101465. When evaluating performance, a graph that reveals a significant amount of information  succinctly is the  cache throughput  for a cluster graph. Performance tools are available on the IBM Techdocs website that take 24 hours of 15-minute  VEHSTATS data, seven days of 1-hour VEHSTATS data, or 90 days of daily summary data  and create a set of charts for you.  The material does not contain any information about the specifics of a Tape Attach model.  However, the other information is still valuable, and did not change, especially how to create  the excel spreadsheet and the charts. See the following Techdocs sites for the performance tools, and the class replay for detailed  information about how to use the performance tools:  GLYPH<SM590000> Tools  GLYPH<SM590000> Class replay  The 24-hour, 15-minute data spreadsheets include the cache throughput chart. Figure 11-31  shows the cache throughput that was plotted from VEHSTATS.  Figure 11-31 Cache throughput plotted from VEHSTATS Chapter 11. Monitoring  679