Monitor I/O wait on NT

KlausErichsen

New Member
For clearing poor performance on a db machine, I like to find out how much the system is waiting for the disk to answer request.

Under Unix I can easily use vmstat or nmon to see the "wait for io". How can I see this under NT Server?

Regards
Klaus
 
Klaus,

Firstly, please note, I am not a DBA, and don't know much about low-level stuff.

My understanding from a scoot around the net is that IO WAIT time is not recorded in Windows, however as it is defined (to my understanding) as the amount of time the processor is idle while io operations are in progress, then you should be able to infer an IO Wait issue (though not exact statistics) by monitoring processor usage during high disk activity.

eg. if the processor is relatively inactive while db is being heavily accessed, then there may be an IO Wait issue.

You monitor system performance in windows (I'm on XP here, not NT) through in-built utilities like the Task Manager (eg. Performance tab), or Admin Tools > Performance; or through 3rd party utilities like the excellent free tools available through sysinternals (now Microsoft owned):
http://www.microsoft.com/technet/sysinternals/default.mspx

eg. filemon, diskmon, process explorer, etc.

HTH until someone more knowledgeable pops by.
 
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