How NTFS reserves space for its Master File Table (MFT) - The Diigo Meta page

• 04 Aug 13
  

  Murray Smithers

  Folders It Computer Software Imported NTFS

• 30 Nov 09
  

  Navneet Kumar

  Microsoft Windows NTFS Disk FileSystem

  • In Windows XP and in Windows Server 2003, the defrag utility defrags the MFT
  • A defrag operation on the MFT combines an MFT file into 1 and prevents it from  being stored in multiple places that are not sequential on disk. In this class  of operation, the MFT file is more sequential. However, it is exactly the size  that the MFT file was before the defrag operation.
    
  • 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
  • As files are added to an NTFS volume, more entries are added to the MFT and so  the MFT increases in size. When files are deleted from an NTFS volume, their MFT  entries are marked as free and may be reused, but the MFT does not shrink. Thus,  space used by these entries is not reclaimed from the disk
  • Volumes with a small number of relatively large files exhaust the unreserved  space first, while volumes with a large number of relatively small files exhaust  the MFT zone space first
  • If the unreserved space becomes full, space for user files and directories  starts to be allocated from the MFT zone competing with the MFT for allocation.  If the MFT zone becomes full, space for new MFT entries is allocated from the  remainder of the disk, again competing with other files.
    

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• 29 Jul 09
  

  Garrett A

  defragmentation windows file system

• 03 Jun 09
  

  Graham Perrin

  Microsoft Windows NTFS MFT fragment 2009

  • utilities  that defragment NTFS volumes cannot move MFT entries
  • fragmentation of the MFT can impact performance
  • NTFS reserves 12.5 percent of the volume for exclusive use of the  MFT
  • unless the remainder of the volume is completely used up

    • So: it is very important to always have a reasonable amount of free space on your Windows XP startup disk.
    Add Sticky Note
  • Disk  Defragmenter displays "green"
  • MFT, pagefile.sys
  • "MFT Zone" or reserved space  for "MFT Expansion"
  • The defragmentation report
  • not mention the MFT Zone

  7 more annotations...

Public Stiky Notes

• 
  Graham Perrin on 2009-06-03
  So: it is very important to always have a reasonable amount of free space on your Windows XP startup disk.

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