Common questions

What is disk time in Performance Monitor?

What is disk time in Performance Monitor?

The disk performance counters time the responses by using a 100 nanosecond precision counter, and then report the cumulative statistics for a given sample time. This sample time could go over 100 percent if, for example, you have 10 requests that completed in 2 milliseconds each in a 10 millisecond sampling interval.

How do I measure disk queue length?

Go to server –>CMD–>perfmon –>ADD –>Physical Disk [performance object]–> AVG disk Queue lenth[counter]. If you don’t have anything setup before the problem to have a baseline the counters won’t help you much (if at all).

How do I reduce disk queue length?

Like I mentioned before, you can decrease your disk usage by making effective use of indexes, studying execution plans, and hardware. Also, just as a note, Current Disk Queue Length, and Avg. Disk Write Queue Length are not percentages in perfmon. You can increase the scale of the graph to see the actual values.

What Is percent disk time?

“Physical Disk: %Disk Time This performance counter is the percentage of elapsed time that the selected disk drive was busy servicing read or writes requests. A general guideline is that if this value is greater than 50 percent, it represents an I/O bottleneck.”

What is active time of disk?

Disk active time is the time the HDD is working. The higher the time/percentage, the more you utilize the HDD. If you hit 99%, you are actually bottle-necked by the read/write performance of your HDD.

What does a long queue length indicate?

If the processor queue length exceeds the value recommended above, it generally indicates that there are more threads than the current processor can service in an optimal way.

What is the queue length in local diskaverage?

“Local DiskAverage Disk Queue Length” is the average number of both read (Avg. Disk Read Queue Length) and write (Avg. Disk Write Queue Length) requests that were queued for the selected disk during the performance data interval. Unlike Current Disk Queue Length, Avg. Disk Queue Length is a derived value and not a direct measurement.

What should the queue length be on raid?

However, if the Avg. Disk Queue Length is greater than 2 per hard disk for a prolonged period of time, it may produce a bottlenecked system. If you have a RAID system with 8 disks, the Avg. Disk Queue Length should not exceed 16.

How to find the avg.disk queue time?

Use the following formula to find the Avg. Disk Queue Time: Avg. Queue Time = Disk Queue Length x Avg. Disk sec/Transfer. This will provide you with a relative performance measurement and should be compared with other hard disk drives in your system. The higher the number of requests waiting in the command queue, the slower the disk performance.

What’s the average queue length for a VMware Server?

Ours averages 5-10 and spikes to 50 during these slowness times. All our servers are VMware, its on a SAN with SSD drives so what can I do to resolve this. Its just on the drive that that data is on so we’ve been considering creating another drive and splitting up the users profile folders or do we need another separate server?