Tuning the Storage Subsystem - Expert Oracle RAC Performance Diagnostics and Tuning - page 377

In Figure 12-12 , the response-time chart displays I/O responses in milliseconds per operation. The throughput
chart, which is the second chart in Figure 12-12 , displays I/O throughput in megabits per second. There are two other
charts: operations per second list the number of I/O operations performed by second and the operation size chart
graphs the I/O operation size in megabits.
Similar to the diskgroup-level statistics illustrated in Figure 12-12 and the I/O statistics displayed in Figure 12-11 ,
statistics can also be viewed from OEM. Figure 12-13 shows response time, throughput, and operation-size statistics at
the disk level within a diskgroup.
Figure 12-13. OEM - Disk-level statistics