How many HANDLES is too many?

Task manager allows you to see how many handles are in use.
Too many handles can give rise to Virtual memory errors, and eventually lead to crashes.
Where can I find any guidance on what sort of figure should be regarded as a warning level.
I understand there is no fixed value, it clearly depends on your virtual memory settings, but there must be some sort of rough guidance ?
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For Windows NT the maximum is 10,000

For XP it's 18,000:
"To use this hotfix, you must create or modify the following registry values to specify the number of NT User handles that you want to allow. The maximum number is 18,000. "

Does that help?
Microsoft server tuning guide, containing more than you're looking for but should be useful in some manner:

I would log the usage (for a week or even a month) and then set the limit at 10% over the max value shown in your logging. if your server is performing fine now then this is the best time to log performance data and then later you can compare results from a "known good" state. You can adjust values as you get alerts that turn out to be simply higher usage, but it would be values set from your specific environment.
dcp002Author Commented:
Thanks for suggestions on determining what is "normal" for my system.  The link you give - whilst interesting - all refers to Windows 2003 Network File System.

However, I already have an application with a "handle leak"- i.e. gaining a 2000-3000 handles per day on a Windows 2000 server. The server crashed recently, but I do not know how many handles it had just before it crashed. Whilst the real answer is to get the app fixed (and that is in hand with the software supplier) until that is sorted I am trying to judge how often I need to re-start the offending app. to safely prevent it reaching the (unknown) point where it crashes the server.

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Sorry what I should have suggested is using Perfmon, take a look at this (more relevant I promise) link:
dcp002Author Commented:
That gives a good way to monitor how the handles are growing - but I still do not know how many handles is danger level.
Is it  10,000   or    100,000   or 1,000,000 ?
Or is the number of handles on its own meaningless - should I just be monitoring Virtual memory usage ?
dcp002Author Commented:
Thanks to The IT Garage for a few useful comments.
However, I do not feel the question has really been answered.
I was looking for a very rough idea of how many handles is danger level - e.g.
10,000 / 100,000 / 1 million / etc.

As no comments for 2 weeks now, I propose to request closure of this question in a few days unless something significant appears.
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