If the fragments of a file are over 64 MB in size, the file is not defragmented if using the GUI Microsoft has stated that this is because there is no discernible performance benefit since the time seeking such large chunks of data is negligible compared to the time required to read them. The user interface has been simplified, with the color graph, progress indicator, disk analysis and fragmentation information being removed entirely. In Windows Vista, Disk Defragmenter includes an option to automatically run at scheduled times using Task Scheduler and uses low CPU priority and the newly introduced low priority I/O algorithm so that it can continue to defrag using reduced resources (less CPU and disk read/write activity) when the computer is in use. In Windows XP, if the Master File Table (MFT) is spread into multiple fragments, defrag.exe and the GUI version can combine the MFT fragments during defragmentation. A command-line tool, defrag.exe, has been included, providing access to the defragmenter from cmd.exe and Task Scheduler. NTFS metadata files can also be defragmented. It no longer relies on the Windows NT Cache Manager, which prevented the defragmenter from moving pieces of a file that cross a 256KB boundary within the file. Windows Disk Defragmenter was updated to alleviate some restrictions. EFS encrypted files are not defragmented.Moving a single file cluster also moves the 4 KB part of the file that contains the cluster. It is not possible to perform fine-grained movement of uncompressed NTFS file data in Windows 2000.Defragmenting NTFS volumes with cluster sizes larger than 4 kilobytes (KB) is not possible.In addition, the Windows 2000 version has the following limitations which were removed in Windows XP: Unlike previous versions, the GUI version in Windows Vista does not display a map of disk fragmentation, nor does it display progress during defragmentation.However, the command line utility since Windows XP and later can be scheduled. The GUI version prior to Windows Vista cannot be scheduled.Only local volumes can be defragmented network volumes are not supported.Prior to the Windows Vista release, only one volume could be analyzed or defragmented at a time and only one instance could run.In particular, this includes the registry, page file and hibernation file. It does not defragment files residing in the Recycle Bin or files that are in use.In Windows 2000 and later operating systems, Disk Defragmenter has the following limitations: Making files contiguous so that they can be read without unnecessary seeking.Obeying a user-provided table of file descriptions to emphasize or ignore.Moving infrequently used files further from the directory area.one third of the way in, so that average head travel to data is halved compared to having directory information at the front. Moving this spot into the center of the data, i.e. Moving all the index or directory information to one spot.The Disk Defragmenter in Windows 2000 was a stripped-down licensed version of Diskeeper, licensed from Diskeeper Corporation. This version had the limitation that if the contents of the drive changed during defragmentation, it rescanned the drive and restarted the process from where it left off. It could be scheduled using a Maintenance Wizard and supported command line switches. Debutĭisk Defragmenter also shipped as part of Windows 95, Windows 98 and Windows Me. However, Windows NT 4.0 did not provide a graphical or command-line user interface. Microsoft included file system control (FSCTL) commands to move clusters in the Windows NT 4.0 kernel, which worked for both NTFS and FAT32 partitions. Executive Software, later renamed Diskeeper Corporation, released Diskeeper defragmentation software for Windows NT 3.51, which shipped with a customized version of the NT kernel and file system drivers that could move clusters. Versions through Windows NT 3.51 did not have an application programming interface for moving data clusters on hard disks. Initial releases of Windows NT lacked a defragmentation tool. Windows NT, however, did not offer a Defrag utility, and Symantec was suggested by others as a possible alternative for the utility. Several third party software developers marketed defragmenters to fill this gap. Microsoft's MS-DOS did not defragment hard disks. As early as the end of 1982, the IBM PC DOS operating system that shipped with early IBM Personal Computers included a Disk Volume Organization Optimizer to defragment the 5¼-inch floppy disks that those machines used.
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