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Take over PAGE FILE

OSR_Community_UserOSR_Community_User Member Posts: 110,217
my goal is to completely take over the role of the page file in the local
disk and substitute it with one on a remote machine
("REDIRECT" the page file).

in order to do so I first want to mirror every thing and compare my results
with ones from disk.

as I understand I need to copy the memory from the IRP->MDL in order to
redirect reads, and copy to it in order to supply writes.
So - in the completion routine I used the MmGetMdlByteCount,
MmGetMdlByteOffset, MmGetMdlVirtualAddress and MmGetSystemAddressForMdlSafe
to look at MDL values. but these procedures get my computer stuck.
I don't understand why ???

I am not yet mirroring the page file but I thought to do so with
TdiCopyBufferToMdl and TdiCopyMdlToBuffer - any reason why these should not
work ???

another problem I have is that during the Dispatch routine for
IRP_MJ_WRITE/READ I can extract the offset and length of the section that
needs to be written/read to/from the PAGE FILE from the
PIO_STACK_LOCATION->Parameters.Read.*
In the completion routine these are no longer valid. WHY?
Can I get them from the MDL?

Ori Zimmels [email protected]
Tandem Labs Israel Phone: (972) 4-832-3050 #207
Tandem Computers Fax: (972) 4-822-5006
a Compaq Company
Gutwirth Science Park - The Technion
Haifa 32000
Israel

Comments

  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    >my goal is to completely take over the role of the page file in the local
    >disk and substitute it with one on a remote machine
    >("REDIRECT" the page file).

    If I understand you correctly you are filtering out the requests to the page
    file from an file system filter. Have you instead considered to put the
    pagefile on its own virtual disk and redirect that disk over the network?
    Wouldn't that mean less file system stuff to fight with?

    ______________________________________________________
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  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    Since I am new at this I decided for some reason to do it this way.
    the advantages of this way is that if you have a computer dedicated as a
    memory bank (RAM SERVER) and surrounding it are PAGE FILE CLIENTS, these
    client can continue as usual. the server can manage who gets what , when. if
    a client gets memory his page files are redirected and if the memory is
    taken back the pages are written back to local disk and he continues using
    his local disk etc.

    Now if I did it by a virtual page file (which I have no idea how to do it
    and would be glade if you could outline the main points for it)
    it would always have to be there for the computers use ????



    Ori Zimmels [email protected]
    Tandem Labs Israel Phone: (972) 4-832-3050 #207
    Tandem Computers Fax: (972) 4-822-5006
    a Compaq Company
    Gutwirth Science Park - The Technion
    Haifa 32000
    Israel


    -----Original Message-----
    From: Henrik Eriksson [mailto:[email protected]]
    Sent: Wednesday, March 08, 2000 11:05 PM
    To: File Systems Developers
    Subject: [ntfsd] Re: Take over PAGE FILE


    >my goal is to completely take over the role of the page file in the local
    >disk and substitute it with one on a remote machine
    >("REDIRECT" the page file).

    If I understand you correctly you are filtering out the requests to the page

    file from an file system filter. Have you instead considered to put the
    pagefile on its own virtual disk and redirect that disk over the network?
    Wouldn't that mean less file system stuff to fight with?

    ______________________________________________________
    Get Your Private, Free Email at http://www.hotmail.com


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    You are currently subscribed to ntfsd as: [email protected]
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