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  • #2074716

    Missing Disk Space


    by david.duong ·

    I have 31 Gig in my raid 5 configuration.
    When i right click on the whole drive it show 26 Gig use and 5 Gig of free space.
    If I use the tree size utilty it show 20 Gig use and 5 Gig of free space. I went back to the drive and check the property of every folder it add up to only 20 Gig use (so the tree size utility was correct).
    What is taking up the 6 Gig that NT report when I check the property of the drive, but does not add up if i check folder by folder?

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  • Author
    • #3776245

      Missing Disk Space

      by aaron v ·

      In reply to Missing Disk Space

      When you say right click on the drive, which utility are you using? Is the tree command counting all hidden files and directories, as well as system files?

      My experience with tree has always been disapointing, I would be more apt to believe thatthe drive properties and Disk Administrator are correct…

      I am going out on a limb and assuming you are using harware RAID and not NT’s software RAID, So I will not talk about that…

    • #3776168

      Missing Disk Space

      by dash242 ·

      In reply to Missing Disk Space

      This might not answer your question, but it is what I would check next. Go to and download the freeware program. It will search the drive for files or folders with alternate data streams. An alternate data stream can be used to hide data in a file without it showing up in a dirlist or by right clicking the file and selecting properties. Of course, this only applies to NTFS partitions.

      Good luck.

    • #3777833

      Missing Disk Space

      by davew ·

      In reply to Missing Disk Space

      The pagefile takes up space, but probably not the amount that is “missing”. Overhead for NTFS, such as ACLs will take up space too.

    • #3778833

      Missing Disk Space

      by tedbovis ·

      In reply to Missing Disk Space

      What you are seeing is the difference between actuall physical file sizes, when you add up all the files on a drive you will get the true size of the contents, but when you click on the drive you are reading the space that these files take ?
      I don’t remember the exact figures but this is all dependant on your cluster sizes on the drives, 4k I think for NTFS, when you go to FAT16 they can be as big as 32K, this means that a 1K file should take 1K of storage space but is doesn’t ! it takes 4K, hence the smaller your files the more space you waste, try and copy 100Mb of small
      files from an NTFS drive to a FAT16 drive and you will soon see what I’m getting at. this is always a considereation when copying data between file systems (NT to Win95).
      I’m sure someone will be able to confirm the details 🙂

    • #3778808

      Missing Disk Space

      by ryank ·

      In reply to Missing Disk Space

      In NTFS partitions quite a bit of disk space is taken up by the MFT (master file table). If you want to see it use a utility like Diskkeeper and do a disk analisys. It will be very obvious where the disk space went. When you do a report on the drive as a whole it shows you actual used space including the MFT. When you get all of the file and folder sizes you get just the “visible” file sizes.

      In FAT partitions you have unusable space left over in clusters.

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