Hi,
I'm trying to purge a specific file data cached by the OS...
How do I accomplish that? I've tried to use various techniques (incl setting
the flag FILE_NO_INTERMEDIATE_BUFFERING) but the data is still cached. I'm
trying to force the system to re-read data in a dvdrom.
Apparently, the DVD rom won't be accessed if part of the data (few hundred
megs) are cached in the file system. I want this to be accssed each time.

cheers,
Kenny

Re: How to purge file cache by Maxim

Maxim
Thu Aug 04 14:34:53 CDT 2005

You cannot do this with 100% reliability. If the app has mmaped the file -
then there is no ways of doing this.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com

"Kenny Liew" <Kenny Liew@discussions.microsoft.com> wrote in message
news:F6A393B1-25AD-4C3E-BEE9-B18C827F1BFD@microsoft.com...
> Hi,
> I'm trying to purge a specific file data cached by the OS...
> How do I accomplish that? I've tried to use various techniques (incl setting
> the flag FILE_NO_INTERMEDIATE_BUFFERING) but the data is still cached. I'm
> trying to force the system to re-read data in a dvdrom.
> Apparently, the DVD rom won't be accessed if part of the data (few hundred
> megs) are cached in the file system. I want this to be accssed each time.
>
> cheers,
> Kenny



Re: How to purge file cache by KennyLiew

KennyLiew
Fri Aug 05 11:20:02 CDT 2005

Thanks...
What I'm after is an app which does reading, of a file using FSD- hence i'm
assuming that the file won't be memory-mapped into the memory.
I think mounting and dismounting the drive would purge the cache, but this
is a fairly big operation... wondering if there's a better way to do it.
This is evident if you try to copy some large files, cancelling it halfway
and do a re-copy would take shorter time as the reading is done via cache...
but if you disable the dvdrom, and re-enable it, the copy time would take as
long as the first time.

"Maxim S. Shatskih" wrote:

> You cannot do this with 100% reliability. If the app has mmaped the file -
> then there is no ways of doing this.
>
> --
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> maxim@storagecraft.com
> http://www.storagecraft.com
>
> "Kenny Liew" <Kenny Liew@discussions.microsoft.com> wrote in message
> news:F6A393B1-25AD-4C3E-BEE9-B18C827F1BFD@microsoft.com...
> > Hi,
> > I'm trying to purge a specific file data cached by the OS...
> > How do I accomplish that? I've tried to use various techniques (incl setting
> > the flag FILE_NO_INTERMEDIATE_BUFFERING) but the data is still cached. I'm
> > trying to force the system to re-read data in a dvdrom.
> > Apparently, the DVD rom won't be accessed if part of the data (few hundred
> > megs) are cached in the file system. I want this to be accssed each time.
> >
> > cheers,
> > Kenny
>
>
>