Re: Windows running without a pagefile by Carl
Carl
Fri Feb 03 03:15:48 CST 2006
At some point very early during the boot process (possibly even as early as
NTLDR before paging is enabled or somewhere in Phase0 or Phase1
initialization), the OS examines the beginning of the pagefile. If it finds
a particular signature, it recognises that there is a dump file written to
the paging file. The dump file is copied from the paging file and written to
the mini-dump or large dump locations which are described by the registry.
The paging file must be at least the same size as the dump being created, so
64 Kb, total size of kernel memory or physical memory size. If I remember
rightly, the kernel foot print is somewhere between 64 and 128 Mb on most XP
systems, so you might be able to get a kernel memory dump working.
If the PCI card is available at boot and your ram disk driver is loaded at
boot and the OS is configured to use your ram disk as the paging file home,
then things are set up so that it might work for you.
Your Ram Disk driver would need to be a boot start driver and provide the
ram disk at the time that the OS looks for a memory dump signature in the
paging file. Obviously, your PCI card would need to be up and running at
this time too.
Carly
"Daniel" <Daniel@discussions.microsoft.com> wrote in message
news:EE4EF35C-03C6-4E8F-98EA-8ACAB24C05F4@microsoft.com...
> Thanks for the reply.
> I have created a Ramdisk that uses the 128 MB memory of a PCI card. I keep
> Windows page file (about 96 MB) on this ramdisk. Windows boot from a "Read
> only" SDI remote boot image (diskless system). If Windows crash, I want
> Windows to generate the crash dump at the next boot. The card's memory is
> not
> reset when the system is rebooted so the page file should have the crash
> info
> at the next boot.
> How does Windows know at boot that there was a crash and generates the
> dump from the pagefile?
> I need to get a mini or kernel dump file for analysis. I really appreciate
> any other idea to get the crash dump.
>
> --
> Thanks,
>
> Daniel
>
>
> "Carl Woodward" wrote:
>
>> Well, besides you being limited to only being able to use the physical
>> RAM
>> in that the machine rather than the double or so provided by having a
>> paging
>> file, the paging file is used to store kernel memory dumps, these are
>> retrieved from the paging file when the machine next boots.
>>
>> There could well be more, but they are the first two that come to mind.
>>
>> Carly
>>
>>
>> "Daniel" <Daniel@discussions.microsoft.com> wrote in message
>> news:C75DBCC3-C3A1-418D-B75F-C92B46770FD2@microsoft.com...
>> > Hi,
>> >
>> > What are the limitations of a system running windows without a
>> > pagefile?
>> >
>> > --
>> > Thanks,
>> >
>> > Daniel
>>
>>
>>