Product guide

Identifying a storage array performance problem 71
Reporting on Your Datacenter
Figure 46 Graph of cache hit ratio on the Symmetrix array disk
4. In the bottom Metrics pane, selects read hits per second and read misses per
second to view the number of times device 0x011 found the data in the array
cache (read hits) and the number of times the data had to be retrieved from the
disk (read misses).
Clicks the Graph per object ( ) button. A new graph appears showing that
there were read misses at 9 A.M. and 6 P.M., which caused the cache hit ratio to
fall Figure 47 on page 72.