Disk Defragmenter (Windows)

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Disk Defragmenter
Defrag icon.png
Windows Disk Defragmenter.png
Disk Defragmenter in Windows 10
Developer(s) Microsoft
Operating system Microsoft Windows
Type Defragmentation software
Website www.microsoft.com.br

Disk Defragmenter is a utility in Microsoft Windows designed to increase access speed by rearranging files stored on a disk to occupy contiguous storage locations, a technique called defragmentation. Defragmenting a disk minimizes head travel, which reduces the time it takes to read files from and write files to the disk. [1] Beginning with Windows XP, Disk Defragmenter also reduces system startup times.[ citation needed ]

Utility software is system software designed to help to analyze, configure, optimize or maintain a computer. It is used to support the computer infrastructure - in contrast to application software, which is aimed at directly performing tasks that benefit ordinary users. Utilities often form part of application systems however. For example a batch job may run user-written code to update a database and may then include a step that runs a utility to back up the database, or a job may run a utility to compress a disk before copying files.

Microsoft Windows is a group of several graphical operating system families, all of which are developed, marketed, and sold by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows NT and Windows Embedded; these may encompass subfamilies, e.g. Windows Embedded Compact or Windows Server. Defunct Windows families include Windows 9x, Windows Mobile and Windows Phone.

A computer file is a computer resource for recording data discretely in a computer storage device. Just as words can be written to paper, so can information be written to a computer file. Files can be edited and transferred through the internet.

Contents

From Windows 8, the program was renamed to Defragment and Optimize Drives.

Early history

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. Microsoft's MS-DOS did not defragment hard disks. Several third party software developers marketed defragmenters to fill this gap. MS-DOS 6.0 introduced Defrag. Windows NT, however, did not offer a Defrag utility, and Symantec was suggested by others as a possible alternative for the utility. [2]

IBM PC DOS

IBM PC DOS is a discontinued operating system for the IBM Personal Computer, manufactured and sold by IBM from the early 1980s into the 2000s. Before version 6.1, PC DOS was an IBM-branded version of MS-DOS. From version 6.1 on, PC DOS became IBM's independent product.

IBM Personal Computer personal computer

The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981. It was created by a team of engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida.

Floppy disk disk storage medium

A floppy disk, also known as a floppy, diskette, or simply disk, is a type of disk storage composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic enclosure lined with fabric that removes dust particles. Floppy disks are read and written by a floppy disk drive (FDD).

Initial releases of Windows NT lacked a defragmentation tool. Versions through Windows NT 3.51 did not have an application programming interface for moving data clusters on hard disks. [3] Executive Software, later renamed Diskeeper Corporation, released Diskeeper defragmentation software for Windows NT 3.51, [3] which shipped with a customized version of the NT kernel and file system drivers that could move clusters.

Windows NT is a family of operating systems produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-user operating system.

Windows NT 3.51 32-bit cross-platform operating system developed by Microsoft

Windows NT 3.51 is the third release of Microsoft's Windows NT line of operating systems. It was released on 30 May 1995, nine months after the release of Windows NT 3.5, and three months before the release of Windows 95. The release provided two notable feature improvements; firstly NT 3.51 was the first of a short-lived outing of Microsoft Windows on the PowerPC architecture. The second most significant enhancement offered through the release was that it provides client/server support for interoperating with Windows 95, which was released three months after NT 3.51. Windows NT 4.0 became its successor a year later; Mainstream support for Windows NT 3.51 Workstation ended on 31 December 2000 and extended support 31 December 2001. Mainstream support for Windows NT 3.51 Server ended on 30 September 2000 and extended support 30 September 2002.

In computer programming, an application programming interface (API) is a set of subroutine definitions, communication protocols, and tools for building software. In general terms, it is a set of clearly defined methods of communication among various components. A good API makes it easier to develop a computer program by providing all the building blocks, which are then put together by the programmer.

Microsoft included file system control (FSCTL) commands to move clusters in the Windows NT 4.0 kernel, [3] which worked for both NTFS and FAT32 partitions. However, Windows NT 4.0 did not provide a graphical or command-line user interface. [3]

Windows NT 4.0 pre-emptive, graphical operating system by Microsoft

Windows NT 4.0 is an operating system that is part of Microsoft's Windows NT family of operating systems. It was released to manufacturing on July 31, 1996. It was Microsoft's primary business-oriented operating system until the introduction of Windows 2000. Workstation, server and embedded editions were sold; all editions feature a graphical user interface similar to that of Windows 95.

NTFS is a proprietary file system developed by Microsoft. Starting with Windows NT 3.1, it is the default file system of the Windows NT family.

Debut

Disk Defragmenter also shipped as part of Windows 95, Windows 98 and Windows Me. It could be scheduled using a Maintenance Wizard and supported command line switches. [4] 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. [5]

Windows 95 operating system from Microsoft

Windows 95 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of operating systems. The first operating system in the 9x family, it is the successor to Windows 3.1x, and was released to manufacturing on August 15, 1995, and generally to retail on August 24, 1995. Windows 95 merged Microsoft's formerly separate MS-DOS and Windows products, and featured significant improvements over its predecessor, most notably in the graphical user interface (GUI) and in its simplified "plug-and-play" features. There were also major changes made to the core components of the operating system, such as moving from a mainly co-operatively multitasked 16-bit architecture to a 32-bit preemptive multitasking architecture.

Windows 98 fifth iteration of the Microsoft Windows operating system

Windows 98 is a graphical operating system developed by Microsoft as part of its Windows 9x family of operating systems. It is the successor to Windows 95, and was released to manufacturing on May 15, 1998, and to retail on June 25, 1998. Like its predecessor, Windows 98 is a hybrid 16-bit and 32-bit monolithic product with the boot stage based on MS-DOS. The startup sound for Windows 98 was composed by Microsoft sound engineer Ken Kato, who considered it to be a "tough act to follow".

The Disk Defragmenter in Windows 2000 was a stripped-down licensed version of Diskeeper, licensed from Diskeeper Corporation. It uses the following techniques: [3]

Windows 2000 personal computer operating system by Microsoft released in 1999

Windows 2000 is an operating system that was produced by Microsoft as part of the Windows NT family of operating systems. It was released to manufacturing on December 15, 1999, and launched to retail on February 17, 2000. It is the successor to Windows NT 4.0.

  1. Moving all the index or directory information to one spot. Moving this spot into the center of the data, i.e. one third of the way in, so that average head travel to data is halved compared to having directory information at the front.
  2. Moving infrequently used files further from the directory area.
  3. Obeying a user-provided table of file descriptions to emphasize or ignore.
  4. Making files contiguous so that they can be read without unnecessary seeking.

In Windows 2000 and later operating systems, Disk Defragmenter has the following limitations:

In addition, the Windows 2000 version has the following limitations which were removed in Windows XP: [7]

Windows XP and Server 2003

Windows Disk Defragmenter was updated to alleviate some restrictions. [8] 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. NTFS metadata files can also be defragmented. A command-line tool, defrag.exe, has been included, [9] providing access to the defragmenter from cmd.exe and Task Scheduler. 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. [10]

Windows Vista and Server 2008

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. The user interface has been simplified, with the color graph, progress indicator, disk analysis and fragmentation information being removed entirely.

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. [11] The result, however, is that Disk Defragmenter does not require a certain amount of free space in order to successfully defrag a volume, unlike performing a full defragmentation which requires at least 15% of free space on the volume. The command line utility, Defrag.exe, offers more control over the defragmentation process, such as performing a full defragmentation by consolidating all file fragments regardless of size. [12] This utility can be used to defragment specific volumes or to just analyze volumes as the defragmenter would in Windows XP.

Disk Defragmenter is maintained by Microsoft's Core File Services. The Windows Vista version has been updated in Windows Vista SP1 to include the improvements made in Windows Server 2008. The most notable of these improvements is that the ability to select which volumes are to be defragmented has been added back. [13] Notably, the Windows Vista defragmenter is much more effective than the version included with XP. [14]

Windows 7 and later

Windows 7 reintroduces the analyze function and showing percent complete of the defragmentation, both of which were removed in Windows Vista. It can also defragment multiple volumes simultaneously.

According to Scott Hanselman of Microsoft, Windows 7 and later do defragment a solid-state disk (SSD) but in a completely different way. There is less incentive for defragmentation of SSDs because file fragmentation has less performance impact on them and they handle a finite number of storage cycles before their lifespan expires. However, file systems cannot support infinite file fragmentation as they reach their metadata limit. In addition, Disk Defragmenter is also responsible for performing the TRIM command on SSDs. [15]

See also

Related Research Articles

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An NTFS junction point is a symbolic link to a directory that acts as an alias of that directory. This feature of the NTFS file system offers benefits over a Windows shell shortcut (.lnk) file, such as allowing access to files within the directory via Windows Explorer, the Command Prompt, etc.

PageDefrag is a program, developed by Sysinternals, for Microsoft Windows that runs at start-up to defragment the virtual memory page file, the registry files and the Event Viewer's logs.

Diskeeper

Diskeeper is a defragmentation program designed for Microsoft Windows. It was developed by Executive Software International, Inc., which later changed its name to Diskeeper Corporation, and is now called Condusiv Technologies.

Robocopy, or "Robust File Copy", is a command-line directory and/or file replication command. Robocopy functionally replaces Xcopy, with more options. It has been available as part of the Windows Resource Kit starting with Windows NT 4.0, and was first introduced as a standard feature in Windows Vista and Windows Server 2008. The command is robocopy.

Contig is a command line defragmentation utility for Windows currently owned by Microsoft subsidiary SysInternals.

File system fragmentation condition where a segmented file system is used inefficiently

In computing, file system fragmentation, sometimes called file system aging, is the tendency of a file system to lay out the contents of files non-continuously to allow in-place modification of their contents. It is a special case of data fragmentation. File system fragmentation increases disk head movement or seek time, which are known to hinder throughput. In addition, file systems cannot sustain unlimited fragmentation. The correction to existing fragmentation is to reorganize files and free space back into contiguous areas, a process called defragmentation.

NTBackup is the built-in backup application introduced in Windows NT around 1997 and part of all subsequent versions up to and including Windows 2000, Windows XP and Windows Server 2003. It uses a proprietary backup format (BKF) to back up files. Files can be backed up to tape, ZIP drives, floppy disks, and hard drives. It also features integration with Task Scheduler and has several command line switches for scheduled automated backups.

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O&O Defrag

O&O Defrag is a Windows defragmentation utility sold by German software developer O&O Software. It has won several awards by PC journals and magazines, and is certified by Microsoft for all its current NTFS-based operating systems, including Windows 2000, Server 2003, Vista, 7, and 10.

Vopt

Vopt is a Windows defragmentation utility sold by Golden Bow Systems. It is one of the oldest defragmentation products, and has supported MS-DOS and all versions of Microsoft Windows. The convenience of quick processing time is offset by less optimal performance, but when used in conjunction with the built-in optimization of the Windows prefetch folder, system performance is maintained without major reorganization of all the files on the drive. In February 2016, the registration key is released free in accordance with the author Barry Emerson's wish.

Defraggler freemium defragmentation utility developed by Piriform

Defraggler is a freemium defragmentation utility developed by Piriform, which can defragment individual files or groups of files on computer system. Defraggler runs on Microsoft Windows; it has support for all versions since Windows XP. It includes support for both IA-32 and x64 versions of these operating systems.

UltraDefrag

UltraDefrag is a disk defragmentation utility for Microsoft Windows. Prior to version 8.0.0 it was released under the GNU General Public License. The only other Windows-based defragmentation utility licensed under the GNU GPL was JkDefrag, discontinued in 2008.

JkDefrag

JkDefrag is a free open-source disk defragmenting utility computer program for Windows. It was developed by Jeroen Kessels beginning in 2004 and is released under the GNU General Public License. The "Jk" part of the utility name is taken from the developer's name, Jeroen Kessels. In 2008, from version 4, much changed from previous versions; JkDefrag was renamed MyDefrag by its developer, and JkDefrag was discontinued, although still available. MyDefrag is closed source freeware. MyDefrag website is defunct as of 2016. The JKdefrag website is still active, but all download files have been removed.

UltimateDefrag is a retail file-system defragmentation utility made by DiskTrix. An older version of the program is available as the UltimateDefrag Freeware Edition.

The following is a comparison of notable file system defragmentation software:

Auslogics Disk Defrag is a freemium software application for Microsoft Windows intended to defragment files and folders on a hard drive, consolidate free space and optimize file placement using different criteria. It is available in both a free and a proprietary "Pro" version with extended functionality.

PerfectDisk is a defragmentation software product for Windows developed by Raxco.

References

  1. ↑ "How to make a computer faster: 6 ways to speed up your PC". Microsoft at work. Microsoft. Retrieved 2011-11-07.
  2. ↑ "How do I run Microsoft Defrag?". Computer Help. Computer Hope. Retrieved 2011-11-07.
  3. 1 2 3 4 5 Russinovich, Mark (20 March 2007). "Inside Windows NT Disk Defragmenting". TechNet. Microsoft. Retrieved 2008-12-09.
  4. ↑ Windows 95 Defrag.exe Command-Line Parameters
  5. ↑ Description of the Disk Defragmenter Tool in Windows 98/Me
  6. ↑ Disk Fragmentation and System Performance
  7. 1 2 3 Disk Defragmenter Limitations in Windows 2000, Windows XP, and Windows Server 2003
  8. ↑ Russinovich, Mark; David Solomon (2005). "Memory Management". Microsoft Windows Internals (4th ed.). Microsoft Press. p. 728. ISBN   0-7356-1917-4.
  9. ↑ "Description of the new command line Defrag.exe included with Windows XP (MSKB283080)". Microsoft. Retrieved 2008-12-09.
  10. ↑ How NTFS reserves space for its Master File Table (MFT)
  11. ↑ Disk Defragmenter FAQs
  12. ↑ "Disk Defragmenter". User Guide. Windows Vista User Guide. 27 January 2007. Archived from the original on 13 February 2007. Retrieved 2007-01-27.
  13. ↑ Disk Defragmenter in Windows Vista and Windows Server 2008
  14. ↑ "21 Essential Steps to Make Your PC Better/Faster/Stronger – Page 4". Maximum PC. Future. 2009-05-28. Archived from the original on 22 June 2011.
  15. ↑ Hanselman, Scott (3 December 2014). "The real and complete story - Does Windows defragment your SSD?". hanselman.com. Sef-published . Retrieved 22 December 2014.
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