• Paged kernel, but no pagefile?

    Author
    Topic
    #485653

    Here’s a conundrum:

    When opening Task Manager and viewing the paging stats for the kernel, I always thought the numbers related to the amount of virtual paged RAM used in the pagefile.sys file.

    This afternoon I was asked to defrag an slow old XP-based machine. To do this on a heavily fragmented machine, I always run a cleanup first. This usually includes removal of System Restore points and removal of the pagefile by setting the amount of disk space reserved for paging operations to zero. Don’t worry, an image is always taken first – this question is is not about risk management.

    Fine and dandy. But, for the first time, something caught my eye which defies my assumption in the first paragraph above. On this machine, Task Manager reports that the kernel is being paged. It can’t be to the pagefile.sys {that doesn’t exsit}. So, now it has got me wondering: what, exactly, do those numbers in Task Manager refer to?

    See attached image:

    32075-paging

    Here you can see the defrag running in the background. To the right you can see I have set zero size for pagefile and I manually confirmed that pagefile.sys was removed. Task Manager on the left shows the kernel being paged. Now, I thought understood the concept of paging, so does this mean that the kernel is in a RAM page, but not loaded into pagefile.sys? There must be a disconnect in my understanding.

    Viewing 1 reply thread
    Author
    Replies
    • #1351416

      Just because there’s no paging file set doesn’t mean Windows won’t use virtual memory when needed, it will setup a temporary paging file.

      On my W7x64 machine with no paging file, ~80% (348MB) of the Windows Kernel is paged. DXDiag (x64) tells me 1.7GB of data is paged, removing the used RAM from that total suggests that some ~300MB is paged. Reference to Russinovich is probably required to get a more accurate figure (and a better explanation than mine).

    • #1351417

      Thanks Satrow, yes Mark Russinovich was going to be on my reading list on this one.

      It does seem likely that virtual memory is being used somewhere. I’m intrigued to understand more.

    Viewing 1 reply thread
    Reply To: Paged kernel, but no pagefile?

    You can use BBCodes to format your content.
    Your account can't use all available BBCodes, they will be stripped before saving.

    Your information: