HP XP P9000 for Compatible High Perf FICON Connectivity Software - Manual (Page 13)

2 About performance monitoring
This topic presents an overview of Performance Monitor and Cache Residency.
Monitoring storage system resources
Performance Monitor enables you to monitor your storage system and collect detailed usage and
performance statistics. If there is a decrease in storage system performance (for example, delayed
host response times), Performance Monitor can help you detect the cause of the problem and
resolve it.
Performance Control uses the data collected by Performance Monitor to identify and resolve
bottlenecks of activity on the ports.
Placing data in cache
Cache Residency enables you to place specific data into user-defined Cache Residency cache
areas, also called cache extents, so that the data is available to hosts at front-end data transfer
speeds. This is called prestaging data in cache.
Prestaging specific data
Cache Residency supports prestaging of data in which specific data is placed into the Cache
Residency cache before it is accessed by the host. When prestaging is used, the host locates the
prestaged data in the Cache Residency cache during the first access, thereby improving
performance.
Figure 2 Cache Residency cache area
CAUTION: Total storage system cache capacity must be increased when using Cache Residency
to avoid data access performance degradation for non-cache-resident data. Cache Residency is
available only on HP XP P9500 storage systems configured with at least 512 MB of cache. The
HP representative configures the maximum allowable Cache Residency area when the cache is
installed.
Both priority mode and bind mode permit prestaging. Prestaging occurs under any of the following
circumstances:
•
When prestaging is performed from the SVP or from Remote Web Console.
•
When the power is turned on.
•
When cache maintenance is performed.
Monitoring storage system resources 13