Defrag increases "used space" as reported by command-line defrag -

Discussion in 'Windows Vista Performance' started by mwhiting001, Apr 14, 2007.

  1. mwhiting001

    mwhiting001 Guest

    Why does defrag increase the disk's "used space"? This happens with both the
    GUI version, and the command-line version. The command line flag "-w"
    results in a greater decrease in used space. I used (command line) defrag c:
    -a -v to generate a report, ran the GUI defrag, and then reran a report. It
    seems that the GUI version repeatably increases "used space" by about .7 GB.
    The "free space" value sometimes doesn't show a decrease, due to the lower
    precision of the number (no decimal values), and the amount of fragmentation.
    The command line version increased "used space" by 1.37, for each of two
    runs that for which I saved the analysis report. The "free space" value IS
    reduced for the more aggressive defrag:
    "defrag c: -w -v. Is this additional used space usable, or is it lost
    forever, or until the disk is reformatted?
     
    mwhiting001, Apr 14, 2007
    #1
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  2. mwhiting001

    mwhiting001 Guest

    I have been wondering why there were no replies to my post (my first, ever).
    In reading it, I realized A) that the subject doesn't indicate that it is a
    question, and B) that I omitted "GB" in the sentence that should have read:
    "The command line version increased "used space" by 1.37GB, for each of two
    runs for which I saved the analysis report.", and C) the post almost reads as
    though it is an answer to something, but I was only trying to give detail on
    how I found the problem.

    I tried to ask Microsoft, but the webpage says to contact the OEM if Vista
    was preinstalled. The response from the OEM didn't address the "problem". Can
    anyone help?

    Thanks, Mike
     
    mwhiting001, Apr 17, 2007
    #2
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  3. mwhiting001

    Rock Guest

    I think it's more because no one knows the answer or has seen this issue
    before. This is a peer to peer user group, and Vista is a new OS.
     
    Rock, Apr 17, 2007
    #3
  4. mwhiting001

    mwhiting001 Guest

    OK, thanks. I'll keep monitoring.

     
    mwhiting001, Apr 17, 2007
    #4
  5. mwhiting001

    Rock Guest

    Ok, good luck.
     
    Rock, Apr 17, 2007
    #5
  6. mwhiting001

    Rock Guest

    "_SPAM" wrote
    Another person recently posted this same issue in the vista.general
    newsgroup. So now there are two of you who have seen this. Maybe it occurs
    across the board, but you are the only ones who have seen it and posted
    about it. I haven't seen any replies to his post yet.
     
    Rock, Apr 17, 2007
    #6
  7. mwhiting001

    DP Guest

    I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
    no switches in the command). I have wondered about it as well and was hoping
    your question would get an answer.

    Besides this being a new OS, I'm guessing that 97 percent of users simply
    use the GUI defrag, not the command-line defrag. I use the the command line
    since I have two disks in three partitions for a total of about 175gb. It
    takes a LONG time to defrag all of that.
    Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
    wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
    by using the command-line method.
    Since the command-line method involves using the right-click "run as
    administrator," that makes the method fairly well hidden to most users.
    Hence my estimate that only 3 percent of us use it.
    I'll keep monitoring as well.
     
    DP, Apr 17, 2007
    #7
  8. mwhiting001

    mikeyhsd Guest

    that would only be successful if you disabled the built in Scheduled Task for defrag run.
    if you have not disabled it, the it is defragging the xp partition as well.








    I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
    no switches in the command). I have wondered about it as well and was hoping
    your question would get an answer.

    Besides this being a new OS, I'm guessing that 97 percent of users simply
    use the GUI defrag, not the command-line defrag. I use the the command line
    since I have two disks in three partitions for a total of about 175gb. It
    takes a LONG time to defrag all of that.
    Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
    wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
    by using the command-line method.
    Since the command-line method involves using the right-click "run as
    administrator," that makes the method fairly well hidden to most users.
    Hence my estimate that only 3 percent of us use it.
    I'll keep monitoring as well.
     
    mikeyhsd, Apr 17, 2007
    #8
  9. I see similar things here (Vista Ultimate, all NTFS). I'm pretty sure it
    doesn't happen all the time, just sometimes. For instance, I just did a
    "defrag -c -w -v" from the command line to see if I could reproduce this
    (I've included the report after these comments). Used Space on the C: drive
    increased from 13.35GB to 13.65GB and Free Space decreased from 6.18GB to
    5.88GB. On the D: drive, Used Space increased from 71.43GB to 73.48GB and
    Free Space decreased from 58.09GB to 56.04GB. In both cases, this is the
    opposite of what I'd expect from defragmenting the drives. My guess is that
    defrag is padding some of the newly defragmented files with free space so
    future increases in file size can be handled without going through a space
    allocation process. Again, that's purely a guess.

    C:\Windows\system32>defrag -c -w -v
    Windows Disk Defragmenter
    Copyright (c) 2006 Microsoft Corp.

    Defragmentation report for volume C: Vista

    Volume size = 19.53 GB
    Cluster size = 4 KB
    Used space = 13.35 GB
    Free space = 6.18 GB
    Percent free space = 31 %

    File fragmentation
    Percent file fragmentation = 0 %
    Total movable files = 68,794
    Average file size = 224 KB
    Total fragmented files = 262
    Total excess fragments = 477
    Average fragments per file = 1.00
    Total unmovable files = 56

    Free space fragmentation
    Free space = 6.18 GB
    Total free space extent = 7,080
    Average free space per extent = 915 KB
    Largest free space extent = 4.39 GB

    Folder fragmentation
    Total folders = 9,761
    Fragmented folders = 2
    Excess folder fragments = 6

    Master File Table (MFT) fragmentation
    Total MFT size = 73 MB
    MFT record count = 68,929
    Percent MFT in use = 92
    Total MFT fragments = 3

    Note: On NTFS volumes, file fragments larger than 64MB are not included
    in the fragmentation statistics

    Defragmentation report for volume C: Vista

    Volume size = 19.53 GB
    Cluster size = 4 KB
    Used space = 13.65 GB
    Free space = 5.88 GB
    Percent free space = 30 %

    File fragmentation
    Percent file fragmentation = 0 %
    Total movable files = 68,794
    Average file size = 224 KB
    Total fragmented files = 0
    Total excess fragments = 0
    Average fragments per file = 1.00
    Total unmovable files = 56

    Free space fragmentation
    Free space = 5.88 GB
    Total free space extent = 7,694
    Average free space per extent = 802 KB
    Largest free space extent = 4.39 GB

    Folder fragmentation
    Total folders = 9,761
    Fragmented folders = 1
    Excess folder fragments = 0

    Master File Table (MFT) fragmentation
    Total MFT size = 73 MB
    MFT record count = 68,929
    Percent MFT in use = 92
    Total MFT fragments = 3

    Note: On NTFS volumes, file fragments larger than 64MB are not included
    in the fragmentation statistics

    Defragmentation report for volume D: My Stuff

    Volume size = 130 GB
    Cluster size = 4 KB
    Used space = 71.43 GB
    Free space = 58.09 GB
    Percent free space = 44 %

    File fragmentation
    Percent file fragmentation = 0 %
    Total movable files = 58,535
    Average file size = 1 MB
    Total fragmented files = 22
    Total excess fragments = 708
    Average fragments per file = 1.01
    Total unmovable files = 10

    Free space fragmentation
    Free space = 58.09 GB
    Total free space extent = 15,589
    Average free space per extent = 4 MB
    Largest free space extent = 19.03 GB

    Folder fragmentation
    Total folders = 6,461
    Fragmented folders = 1
    Excess folder fragments = 2

    Master File Table (MFT) fragmentation
    Total MFT size = 65 MB
    MFT record count = 58,827
    Percent MFT in use = 88
    Total MFT fragments = 3

    Note: On NTFS volumes, file fragments larger than 64MB are not included
    in the fragmentation statistics

    Defragmentation report for volume D: My Stuff

    Volume size = 130 GB
    Cluster size = 4 KB
    Used space = 73.48 GB
    Free space = 56.04 GB
    Percent free space = 43 %

    File fragmentation
    Percent file fragmentation = 0 %
    Total movable files = 58,535
    Average file size = 1 MB
    Total fragmented files = 0
    Total excess fragments = 0
    Average fragments per file = 1.00
    Total unmovable files = 10

    Free space fragmentation
    Free space = 56.04 GB
    Total free space extent = 16,302
    Average free space per extent = 4 MB
    Largest free space extent = 19.03 GB

    Folder fragmentation
    Total folders = 6,461
    Fragmented folders = 1
    Excess folder fragments = 0

    Master File Table (MFT) fragmentation
    Total MFT size = 65 MB
    MFT record count = 58,827
    Percent MFT in use = 88
    Total MFT fragments = 3

    Note: On NTFS volumes, file fragments larger than 64MB are not included
    in the fragmentation statistics




    "_SPAM"
     
    David A. Lessnau, Apr 17, 2007
    #9
  10. "_SPAM"



    See
    http://blogs.technet.com/filecab/ar...s-cover-why-windows-vista-defrag-is-cool.aspx

    The blog says that defrag attempts to prevent copy-on-write by the Volume
    Shadow copy Service (VSS) where possible.
    Whenever this is not possible to prevent, VSS's diff space will increase,
    decreasing available free space.

    The space is not lost forever, it is being used to back up your files that
    have "changed" according to VSS, due to their being moved around by defrag.
    vssadmin.exe will tell you about your shadow storage space. There is a
    default maximum allowed shadow storage space (15% of volume), so you needn't
    fear your free space decreasing until there's none left.


    -Victoria
     
    Victoria House [MSFT], Apr 17, 2007
    #10
  11. mwhiting001

    Rock Guest

    Thanks for the explanation, Victoria.
     
    Rock, Apr 18, 2007
    #11
  12. mwhiting001

    mwhiting001 Guest

    Victoria, I echo Rock's thanks. It is a relief to know that the growth is
    limited. I looked at your reference, followed some of the links, and
    concluded that the additional space is used for a restore-point in case data
    are damaged in the move. Also, thanks for the awareness of other sources of
    info. provided by links in the referenced blog. Thanks to everyone who
    replied, too.

    Mike
     
    mwhiting001, Apr 18, 2007
    #12
  13. mwhiting001

    DP Guest

    Sorry, "what" would only be successful?

    that would only be successful if you disabled the built in Scheduled Task for defrag run.
    if you have not disabled it, the it is defragging the xp partition as well.








    I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
    no switches in the command). I have wondered about it as well and was hoping
    your question would get an answer.

    Besides this being a new OS, I'm guessing that 97 percent of users simply
    use the GUI defrag, not the command-line defrag. I use the the command line
    since I have two disks in three partitions for a total of about 175gb. It
    takes a LONG time to defrag all of that.
    Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
    wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
    by using the command-line method.
    Since the command-line method involves using the right-click "run as
    administrator," that makes the method fairly well hidden to most users.
    Hence my estimate that only 3 percent of us use it.
    I'll keep monitoring as well.
     
    DP, Apr 18, 2007
    #13
  14. mwhiting001

    mikeyhsd Guest

    manually running defrag to prevent defragging your xp drive/partition.
    if you still allow the auto Scheduled Task Defrag to run it will still defrag the xp drive.







    Sorry, "what" would only be successful?

    that would only be successful if you disabled the built in Scheduled Task for defrag run.
    if you have not disabled it, the it is defragging the xp partition as well.








    I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
    no switches in the command). I have wondered about it as well and was hoping
    your question would get an answer.

    Besides this being a new OS, I'm guessing that 97 percent of users simply
    use the GUI defrag, not the command-line defrag. I use the the command line
    since I have two disks in three partitions for a total of about 175gb. It
    takes a LONG time to defrag all of that.
    Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
    wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
    by using the command-line method.
    Since the command-line method involves using the right-click "run as
    administrator," that makes the method fairly well hidden to most users.
    Hence my estimate that only 3 percent of us use it.
    I'll keep monitoring as well.
     
    mikeyhsd, Apr 18, 2007
    #14
  15. mwhiting001

    DP Guest

    I don't.
    Thanks for the tip, tho.

    manually running defrag to prevent defragging your xp drive/partition.
    if you still allow the auto Scheduled Task Defrag to run it will still defrag the xp drive.







    Sorry, "what" would only be successful?

    that would only be successful if you disabled the built in Scheduled Task for defrag run.
    if you have not disabled it, the it is defragging the xp partition as well.








    I have seen it too, using a simple "degfrag c:" in the command prompt (i.e.,
    no switches in the command). I have wondered about it as well and was hoping
    your question would get an answer.

    Besides this being a new OS, I'm guessing that 97 percent of users simply
    use the GUI defrag, not the command-line defrag. I use the the command line
    since I have two disks in three partitions for a total of about 175gb. It
    takes a LONG time to defrag all of that.
    Also, I'm being overly cautious and maybe I shouldnt be. But I'm a little
    wary of having Vista defrag an XP drive (I dual boot), so I avoid doing that
    by using the command-line method.
    Since the command-line method involves using the right-click "run as
    administrator," that makes the method fairly well hidden to most users.
    Hence my estimate that only 3 percent of us use it.
    I'll keep monitoring as well.
     
    DP, Apr 19, 2007
    #15
  16. mwhiting001

    HMT Guest

    The simple way to recover this lost space is to turn System Restore off and
    on again. By the way, when you turn System Restore on in Vista, it does not
    automatically create a Restore Point as with XP. You must create a Restore
    Point manually - something Microsoft should fix. I just discovered the same
    problem as Mike after running defrag c: -r, then defrag c: -w from the
    command prompt. I lost 3.6GB the first defrag and then lost another 1.75GB
    the second defrag. After turning System Restore off and on, my free space
    went from 16% to 41%. This seems like a bug to me - Microsoft, please fix.

    HMT
     
    HMT, Jun 19, 2009
    #16
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