| Subject: clear particular files from the file system cache |
| Group: microsoft.public.winternals |
| Date: 1/8/2008 9:29:03 AM |
| From: =?Utf-8?B?RnVybWFuR0c=?= [Email Address Protection] |
Let's say there's a zzz.exe that I didn't write. It reads c:\largefile.txt. Thus that file is often in the windows file system cache. How can I write an app that clears just that file or just a directory from the windows file system cache? Any pointers or suggestions for where else to post the question would be appreciated. |
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| Subject: Re: clear particular files from the file system cache |
| Group: microsoft.public.winternals |
| Date: 1/8/2008 1:29:32 PM |
| From: "Mathieu CHATEAU" [Email Address Protection] |
Hello, this reminds me older software that claimed to release memory by filling memory and then releasing it, so users could see a lot of memory ram. Windows intenal way to manage cache & standbylist is really good, i don't think you can purge file in cache manually. You may have to fill the memory to obligate Windows to purge the cache. Why do you want to do so ? -- Cordialement, Mathieu CHATEAU English blog: http://lordoftheping.blogspot.com French blog: http://www.lotp.fr "FurmanGG" <FurmanGG@discussions.microsoft.com> wrote in message news:8FB0EC25-E305-4829-BAA8-93330C386D61@microsoft.com... > Let's say there's a zzz.exe that I didn't write. It reads > c:\largefile.txt. > Thus that file is often in the windows file system cache. How can I write > an > app that clears just that file or just a directory from the windows file > system cache? > > Any pointers or suggestions for where else to post the question would be > appreciated. |
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| Subject: Re: clear particular files from the file system cache |
| Group: microsoft.public.winternals |
| Date: 1/8/2008 5:08:28 PM |
| From: DevilsPGD [Email Address Protection] |
In message <F646CD7C-90C5-4A28-99B3-47EDDB39962E@microsoft.com> FurmanGG <FurmanGG@discussions.microsoft.com> wrote: >I have plenty of RAM. Performance with it in the file system cache is great. >I'm trying test on a cold cache. I need to ensure the cache is cold. Honestly, you need to restore the entire drive from a static image in order to ensure a consistent environment. Among other things, this will ensure that the various caches are in the same state. |
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| Subject: Re: clear particular files from the file system cache |
| Group: microsoft.public.winternals |
| Date: 1/9/2008 10:50:58 PM |
| From: DevilsPGD [Email Address Protection] |
In message <6C26BE2A-1EFB-46D5-AD4C-D5902BFAE680@microsoft.com> FurmanGG <FurmanGG@discussions.microsoft.com> wrote: >I'm mainly targeting Win2003. It's some internal application data files for >some other application. I'm trying to tune performance so that it's as good >as possible on a cold cache. > >That Prefetch tip was interesting. I see only one .pf file in that >directory, but inside it, it references many of the application's data files >I'm worried about. So do I understand correctly that the Prefetch thing loads >those files into the windows file system cache on boot? That's interesting to >be aware of. Good tip. > >Regardless, that doesn't solve my problem. I'm wanting to run a performance >test, clear those files out of the windows file system cache via a script or >utility app, then run a slightly different performance test... all automated. Seriously, image the system. There are too many other factors which can occur, a clean image is the only way to guarantee that you're back to the same state you started with in a previous test. |
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| Subject: Re: clear particular files from the file system cache |
| Group: microsoft.public.winternals |
| Date: 1/10/2008 12:46:13 AM |
| From: "Edwin vMierlo [MVP]" [Email Address Protection] |
> > Seriously, image the system. There are too many other factors which can > occur, a clean image is the only way to guarantee that you're back to > the same state you started with in a previous test. sorry, but I fail to see what imaging a disk and restoring has anything to do with file-system-cache ? |
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| Subject: Re: clear particular files from the file system cache |
| Group: microsoft.public.winternals |
| Date: 1/10/2008 5:36:43 PM |
| From: DevilsPGD [Email Address Protection] |
In message <OVtPhz1UIHA.5300@TK2MSFTNGP03.phx.gbl> "Edwin vMierlo [MVP]" <EdwinvMierlo@discussions.microsoft.com> wrote: >> Seriously, image the system. There are too many other factors which can >> occur, a clean image is the only way to guarantee that you're back to >> the same state you started with in a previous test. > >sorry, but I fail to see what imaging a disk and restoring has anything to >do with file-system-cache ? In message <6C26BE2A-1EFB-46D5-AD4C-D5902BFAE680@microsoft.com> FurmanGG <FurmanGG@discussions.microsoft.com> wrote: | Regardless, that doesn't solve my problem. I'm wanting to run a performance | test, clear those files out of the windows file system cache via a script or | utility app, then run a slightly different performance test... all automated. Anyone who has done any sort of serious automated performance testing will tell you how important it is to ensure that your base configuration remains identical between tests. In short, for performance testing where the various caches could come into play, you need to watch for other factors, even the simple act of writing files and deleting them, then doing it again (with identical file sets) will often show non-identical results due to the different state of the file system (even allowing for reboots, clearing of caches, etc) If you happen to be doing this under Vista, you'd also want to ensure that the machine's clock is set identically, otherwise you'll likely get different results late Tuesday night / Wednesday morning then any other time (for example) |
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