HP XP P9500 Storage - Manual (Page 8)

2 About monitoring performance
This chapter provides an overview of Performance Monitor and Cache Residency.
Monitoring resource availability
Performance Monitor tracks your storage system so that you can obtain statistics about the following:
•
Resources in your storage system
•
Workloads on disk and ports
If your system encounters some problem (for example, if server hosts suffer delayed response times),
Performance Monitor can help you detect the cause of the problem.
Prestaging specific data
Cache Residency supports prestaging of data. This option places specific data in the Cache
Residency cache before it is accessed by the host. When prestaging is selected, the host is able
to find the prestaged data in the Cache Residency cache from the first access, thus enhancing its
access performance.
Figure 1 Cache Residency cache area
CAUTION: Increase total storage system cache capacity when using Cache Residency to avoid
data access performance degradation for non-Cache-Residency data. Cache Residency is available
only on P9500 storage systems configured with at least 4 GB of cache. The HP representative
configures the maximum allowable Cache Residency area when the cache is installed.
You can use the prestaging function to make data available from the Cache Residency cache the
first time the host accesses the data. 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
8 About monitoring performance