UltraDefrag is an open source disk defragmenter for Windows NT 4.0 and later operating systems. It makes use of the same defragmenting API used by many other windows defrag utilities, both open and closed source. However, UltraDefrag has two features that make it unique. The first is that it has a kernel mode driver that does most of the work. The second is the ability to run the application at boot up time in a manner similar to chkdsk. This allows for faster defragmentation time and the ability to defragment all files including system files.

UltraDefrag has the following features:

• system files defragmentation (registry, pagefiles...)
• ultra fast NTFS analysis
• fast defragmentation algorithm
• effective volume optimization algorithm
• safety, it can never damage processed files
• simplicity, it can be used without reading the documentation
• ability to defragment single file/directory from the context menu in Explorer
• ability to defragment additional streams attached to NTFS files
• ability to exclude any unimportant fiiles based on flexible filters
• ability to defragment files which have number of fragments above specified threshold
• ability to automatically break defragmentation when the specified time interval elapses
• well readable HTML reports
• powerful command line interface
• ability to automatically hibernate/shutdown PC after a job
• small handy scheduler
• multilingual graphical interface
• little binaries (less than 1 Mb)
• portable version requires no installation
• native 64-bit support on source code level
• open source code licensed under GPL

UltraDefrag supports the following filesystems: FAT12/16/32, NTFS and on Vista UDF. UDF is a file system intended for optical media such as DVDs that unlike ISO9660, is rewriteable. It has also the ability to defragment volumes at boot time allowing you to move many system files that are always locked by the operating system. Actually all files including the registry hives and the pagefile can be scanned at boot time. UltraDefrag can also defragment files and folders compressed by NTFS file system compression. And can even defragment floppies, although doing so is not particularly useful.

UltraDefrag runs on Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008 and Vindows 7, including 64 bit versions of Windows. NT 4.0 Alpha is not supported currently.

UltraDefrag can perform 3 jobs: Volume Analysis, Volume Defragmentation and Volume Optimization. Read carefully next chapters to understand how to run them. Here the appropriate algorithms will be discussed.

• Volume Analysis When the analysis job is requested, driver searches for files in specified directory. GUI program analyses all found files, because it needs a full information to redraw the cluster map properly. Console and native interfaces skips all unwanted files filtered out by user defined filters. Therefore these interfaces makes an analysis faster.
• Volume Defragmentation Program's engine defragments files by filling the free space areas at the beginning of the volume with fragmented files contents. To speed up this process, exclude unimportant files (temporary, archives and so on) using filters.
• Volume Optimization This job contains six steps:
  • Initial analysis. The defragmenter collects information about all files on the volume.
  • First optimization step. The program tries to become largest free space area at the beginning of the volume by moving all data from the beginning to the free space areas in the terminal part of volume.
  • Second analysis. This operation updates all information and frees temporarily allocated system space on NTFS.
  • Volume defragmentation. Fragmented files will be defragmented. As described above they will be placed in the leading free space areas, freed on the first optimization step.
  • Second optimization step. Unfragmented files will be moved to the beginning of the volume. They will be placed into the rest of the leading free space areas after files successfully moved at the previous step.
  • Final analysis. This operation updates all information.

  Since the 3.3.0 version of the program this sequence of optimization steps will repeat few times until the end of the volume will be reached. The starting point of an optimization moves forward before repeating the sequence to skip already optimized part of the volume. This highly improves the optimization by making it very effective.

  In spite of this multipass optimization strategy it takes relatively small amount of time.

  Note that Volume Optimization is very effective always, even when processed volume has a small amount of free space.

  Volume optimization algorithm works only on NTFS volumes, because FAT directories aren't moveable.

  NTFS file system is very imperfect. We cannot move internal files, such as $MFT, $Bitmap and other internal files with a '$' sign in the begginning of their names. This is a well known ntfs.sys driver's bug. Free space may be splitted into few small parts by such unmoveable internal files. So you may never become a large free space area to defragment pagefile and other big files. Though there are still two ways to achieve a full volume optimization:

  • The easiest way is very simple. Move all files from selected volume to another disk, than reformat the volume and move all files back. Works fine, except for system volumes that have locked files.
  • The second way requires an additional software: GParted Live CD (open source program) or Partition Magic (commercial software). First of all - reduce the selected volume size as much as possible. This operation will move all data to the beginning of the volume. All system files will be moved too (including $MFT, $Bitmap and so on). Next step - restore size of the selected volume. After this step we will have large contignuous free space area at the end of the volume. Final step - make a boot time defragmentation of the volume using UltraDefrag.

The Ultra Defragmenter's home page is at: http://ultradefrag.sourceforge.net

Please be sure to visit this site for information, documentation, tutorials, news, etc. All Ultra Defragmenter related things are available from there.

For help requests visit our forum: http://ultradefrag.sourceforge.net/forum

Please report all problems and bugs via our bug tracker: http://ultradefrag.sourceforge.net/bugs

The most recent version of this handbook can be obtained from program's SVN repository.