Measures reported by UspPortUsageTest

Performance Monitor tracks host ports and disk subsystem ports to obtain statistics about I/O rates and transfer rates of these ports. If you analyze these I/O rates and transfer rates, you can determine which hosts reports a lot of I/O requests to the disk and which hosts transfer a lot of data to the disk.

Workload information displayed by Performance Monitor is as follows:

I/O rate:The I/O rate indicates how many I/Os are made to the disk in one second. If the I/O rate is high, the hosts might consume a lot of time for accessing disks and the response time might be long.

Transfer rate: The transfer rate indicates the size of data transferred to the disk in one second. If the transfer rate is high, the hosts might consume a lot of time for accessing disks and the response time might be long.

The read hit ratio: For a read I/O, when the requested data is already in cache, the operation is classified as a read hit. For example, if ten read requests have been made from hosts to devices in a given time period and the read data was already on the cache memory three times out of ten, the read hit ratio for that time period is 30 percent. A higher read hit ratio implies higher processing speed because fewer data transfers are made between devices and the cache memory.

Write-Hit Ratio: For a write I/O, when the requested data is already in cache, the operation is classified as a write hit. For example, if ten write requests were made from hosts to devices in a given time period and the write data was already on the cache memory three cases out of ten, the write hit ratio for that time period is 30 percent. A higher write hit ratio implies higher processing speed because fewer data transfers are made between devices and the cache memory.

This test is used to identify the I/O activity and overall statistics of Usp Ports Usage.