HP LeftHand SAN Solutions Support Document - Application Notes - Best Practices for Enabling Microsoft Windows with SAN/iQ®

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9 Chapter: Measuring Performance in a
Windows Environment
Overview
This section describes how to use Perfmon to measure performance on a
Windows system connected to a volume on the SAN.
Using Windows Performance Monitor to Measure SAN Performance
The preferred method to measure application server performance connected to
the SAN is to use Windows Performance Monitor (perfmon.exe) and sample
the appropriate PhysicalDisk counters for the SAN volume(s) in question. The
following are relevant performance counters and what they measure:
Windows
Performance
Counter SAN Measurement Notes
Avg. Disk Sec/
Read
Read I/O Latency of
the volume
Measured in Seconds. Typical
values are in milliseconds.
Avg. Disk Sec/
Transfer
I/O (Read & Write)
Latency of the volume
Measured in Seconds. Typical
values are in milliseconds.
Avg. Disk Sec/
Write
Write I/O Latency of
the volume
Measured in Seconds. Typical
values are in milliseconds.
Avg. Disk Queue
Length
Average # of pending
I/O requests for the
volume
Measured as the raw number.
Current Disk
Queue Length
Current # of pending
I/O requests for the
volume
Measured as the raw number.