Page file

  • Thread starter Thread starter Sean Gahan
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Sean Gahan

I plan on using EWF on CF storage, how do you relocate the page file to a
non protected volume.

Thanks,

Sean Gahan
 
Hi Sean,

If I can remember correctly from one old conversation, page file will bypass
(write trough disk access for performance reasons and not trough volume) EWF
protection. So it can be used on protected volumes.

Regards,
Slobodan
 
KM,
Thanks for the info and thanks for contributing so much to the NG. I read
the NG every day, and I am always impressed at the willingness to help
others that you and Slobodan do on a daily basis.

With warm regards,

Sean Gahan
 
Hi Sean,

Sorry for leading you to probably wrong way.
Today I was told that pagefile is accessed trough FS. I will verify this probably during the weekend.

Regards,
Slobodan
 
Hi Konstantin,

I have been told that pagefile writes go trough filesystem. (So they are overlay-ed in EWF.).
Could you tell me about tests that you used in determining that pagefile works as hibernation file?

Best regards,
Slobodan
 
Hi Slobodan,

You have just gotten to the same confusion I had :-)

See below my last reply to you a while ago on the paging file problem. Now very informative but that was all I could get/guess that
time.

I am still unclear on how the paging is implemented. Why it bypasses EWF.
What I see is that RAM usage does not come up even if I have a lot of page faults (pagefile is used).
With a test app I consumed way more than Available physical memory, and Virtual/Pagefile memory was certainly used. However, I
was not observing the additional RAM usage coming from EWF. Therefore, I assumed paging was bypassing EWF.
Even if I had a small pagefile and after some allocations got "Low Memory.. adjusting the pagefile size.." system message and
the
pagefile was increased to the maximum specified, there was no EWF RAM usage increase.

I thought (guessed and some googling helped) that MM paging writes are implemented with calls to
IoSynchronousPageWrite(IRP_PAGING_IO). But then they definitely should end up calling to FS driver and then to EWF driver.

This is probably a question to comp.os.ms-windows.programmer.nt.kernel-mode. Or to whoever created EWF.

As I also mentioned in that thread
(http://groups.google.com/groups?hl=...2MSFTNGP11.phx.gbl&rnum=1&prev=/groups?q=eXP+
paging%2Bgroup:microsoft.public.windowsxp.embedded.*%26hl%3Den%26lr%3D%26ie%3DUTF-8%26group%3Dmicrosoft.public.windowsxp.embedded.*%
26selm%3DeAMSOyMSEHA.1276%2540TK2MSFTNGP11.phx.gbl%26rnum%3D1) that EWF (enabled) RAM usage does not go up even if I see much of
paging in the system (used just to allocate big chunks of memory).

All this does not really help you but just FYI...
It would be really nice it you could clarify the issue :-) Good luck!

Regards,
Konstantin
 
Slobodan,

:-) It gets funny when we are writing posts the same time :-)

What I did was very simple:
- created an image with EWF RAM Overlay (disabled), pagefile enabled
- FBA, see the pagefile created, EWF -enable
- reboot and watch on the memory usage (pagefile, of course, locked by the system)
- allocate and commit big chunks of memory (a simple test app) to eat all the RAM available and force system to paging
- no RAM usage increase observed expect the memory consumed by the alloc-test app

Does it make a sense?
 
Rightly said and it gets more funny when we read you :) .I guess thats
the most that we can do :-)

KM, how does the pagefile work as an hibernation file.Does this mean
that it is a heavy stuff or it is not giving the additional RAM by
paging.

Regards,
Kesavan
 
Hi Kesavan,

So far it appear that it is giving impression of additional RAM. But there is some serious problem to this that we are trying to
figure out offline. So DO NOT USE THIS approach.
Someone will post back when we figure this out.

Best regards,
Slobodan
 
Hi Slobodan,

Great . Please let us know the updates when something turns out .

Regards,
Kesavan
 
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