Mysterious disk usage RRS feed

  • Question

  • Hi Guys,

    I'm running a Windows 7 machine with 3 physical disk drives. The first drive is the system drive.  The other 2 drives RAID’d into a single drive at RAID 1 with a total space of 2.7 tb.  The three folders on that drive total 600gb yet is shows that I’m using 2.5tb when I look at the drive properties.  I checked the folder options to show hidden files and that didn’t uncover anything.  I also copied all folders over to another drive and sure enough the space used is only 600gb.  Any idea what could be taking up drive space and how I can show those files?  The only thing I think of the is that I’m using Syctoy to back the data up onto a USB drive and its somehow writing hidden files to that same drive?

    Monday, October 22, 2012 7:29 PM

All replies

  • Any ideas would be appreciated.
    Tuesday, October 23, 2012 2:57 PM
  • Hi,

    From your description, I  understand that there are three drives, A, B and C.

    A is used to install the system operation. B and C are used to create the RAID 1.

    I would like to know how much space of drive B and C? 

    Kim Zhou

    TechNet Community Support

    Wednesday, October 24, 2012 6:22 AM
  • Well there are really only 2 logical drives.  C: drive is a 500gb system drive. D: drive is the RAID'd drive...2.7tb total.  I have this configuration on several other machines with no issues as well.
    Wednesday, October 24, 2012 7:11 PM
  • The drive is filling up at around 2 to 5 gb's per day still.
    Monday, October 29, 2012 6:38 PM
  • Hi,

    We may perform Check Disk for a test. It may cost much time.

    1. Run Command prompt as Administrator.

    2. Type in “chkdsk /f /r”

    3. Reboot the system and check if the issue persists again.

    Kim Zhou

    TechNet Community Support

    Tuesday, October 30, 2012 2:19 AM
  • I've done that and it didn't seem to help. The biggest problem and that when I view the folder properties I'm only seeing about 650gb total...yet somehow 2.5 tb is being used.
    Thursday, November 1, 2012 8:55 PM
  • Hi ,

    Please check the System Volume Information folder. 
    Is Volume Shadow Copy Service maintaining diff area files for snapshots? 
    To determine how much space was occupied by vss, run the following command from elevated permission:

    Vssadmin List ShadowStorage

    From the output, please check "Allocated Shadow Copy Storage space" for the RAID drive. 

    If there is no clue, please use WinDirStat (http://windirstat.info/) tool to check the space usage. (In the Options menu, check "Show unknown"). Capture a screenshot.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    • Edited by HuAaron Saturday, November 3, 2012 10:03 AM
    Saturday, November 3, 2012 10:03 AM
  • Ok...shadow storage was only 10gb so I downloaded and ran Windirstat. Its shows shows 77.2% (2tb) of unknown space used...no files, folders, or subfolders at all.  I don't have a way to hot the screenshot though.
    Wednesday, November 7, 2012 6:37 PM
  • I see that file in Windirstat but it won't let me delete it. Any ideas?
    Friday, November 16, 2012 5:44 PM
  • Is there any way to get access to that file?
    Tuesday, November 27, 2012 12:56 AM
  • Maybe I can help :) First install one of these 3 programs. (Your choice which suites you best they are all the same pretty much and free to use)




    Once you have it installed scroll to the bottem of the check list Unchecking everything.

    At the bottem of the list you will see Wipe Free Space Put a check in the box and click run

    This may take close to 2 hours so be prepared to wait.

    I believe you can target the other 2 drives also, if not atleast we got your free space on the system drive cleaned up.

    Also if there is hidden information and files on the drives you can veiw it by editing your folder options.

    double Click target drive>> click tools>> click folder options>> click veiw>> click show all hidden folders files and drivers>> click apply

    Hope this helped a little.

    When was the last time you ran a disk clean up on the target drives? right click the target drive> Click properties>> click disk cleanup > Click more options> Two extra cleaning options there for you to like clean out all old restore points but most recent...

    Might be a virus filling the drives empty space to.

    Also disk usage is diffrence from disk space usage. Actual disk usuage reading 70-100% could be the indexing service bug me and many others have been complaining about Simply disable windows indexing service in services.msc.

    Well thats my take on the subject GL,


    • Proposed as answer by MS_Guru_Tom Wednesday, November 28, 2012 12:58 AM
    Wednesday, November 28, 2012 12:55 AM
  • Hi ,

    Sorry for the late. I saw similar issue before. If there is unknown space, it might be meta files. If this is the case, we can't delete it. Format the disk is the only option. To verify this, please run chkdsk <drive letter> /c /i on that volume. Let me know the output. Maybe I can check if it was metadata file. 

    Bye the way, is there no large files on System volume information folder? Could you capture a screenshot of the Windir ? Thanks. 

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Wednesday, December 5, 2012 1:52 PM
  • Well I've already checked the option for show hidden files, run chkdsk, etc.  It sounds like it might be metadata.  Is there any 3rd party program that will let me delete that file?  The issue is copying that data off and back ussually results in loss of data. There are like a million files on that drive.

    How and why is metadata written anyway? Is is possible to kill the process that does this so I won't have to go through this again?



    Friday, December 7, 2012 9:25 PM
  • Hi Craig,

    To verify if the master file table record ($MFT) consumed the disk space, please run chkdsk against the volume and output may be as follows.

    62809087 KB total disk space.

      22753836 KB in 68739 files.

         44036 KB in 17176 indexes.

             0 KB in bad sectors.

      17743711 KB in use by the system.

         65536 KB occupied by the log file.

      22267504 KB available on disk.

          4096 bytes in each allocation unit.

      15702271 total allocation units on disk.

       5566876 allocation units available on disk.

    The NTFS file system contains at its core, a file called the master file table (MFT). There is at least one entry in the MFT for every file on an NTFS volume, including the MFT itself.

    Because utilities that defragment NTFS volumes cannot move MFT entries, and because excessive fragmentation of the MFT can impact performance, NTFS reserves space for the MFT in an effort to keep the MFT as contiguous as possible as it grows.

    An MFT can be too big if a volume used to have lots of files that were deleted. The files that were deleted cause internal holes in the MFT. These holes are significant regions that are unused by files. It is impossible to reclaim this space. This is at least true on a live NTFS volume. Please copy data to other volumes, format this volume and the restore data back.

    More information for your reference:

    How NTFS reserves space for its Master File Table (MFT)


    Master File Table


    About the Master File Table zone reservation in Windows Vista and Windows Server 2008



    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Saturday, December 8, 2012 4:42 AM