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Other names | Disk Defragmenter |
---|---|
Developer(s) | Microsoft |
Operating system | Microsoft Windows |
Type | Defragmentation software |
License | Proprietary commercial software |
Microsoft Drive Optimizer (formerly Disk Defragmenter) is a utility in Microsoft Windows designed to increase data access speed by rearranging files stored on a disk to occupy contiguous storage locations, a technique called defragmentation. Microsoft Drive Optimizer was first officially shipped with Windows XP.
Defragmenting a disk minimizes head travel, which reduces the time it takes to read files from and write files to the disk. [1] As a result of the decreased read and write times, Microsoft Drive Optimizer decreases system startup times for systems starting from magnetic storage devices such as a hard drive. However, defragmentation is not helpful on storage devices such as solid state drives, USB drives or SD cards that use flash memory to increase speeds, as these drives do not use a head. Doing so may decrease lifespan for these types of devices.
From Windows 8 onwards, the program was renamed to Microsoft Drive Optimizer, with some references changed to say Defragment and Optimize Drives or simply Optimize Drives.
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. At this time, 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 Microsoft Defrag. [2] Windows NT, however, did not offer a Defrag utility, and Symantec was suggested by others as a possible alternative for the utility. [3]
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. [4] Executive Software, later renamed Diskeeper Corporation, released Diskeeper defragmentation software for Windows NT 3.51, [4] which shipped with a customized version of the NT kernel and file system drivers that could move clusters.
Microsoft included file system control (FSCTL) commands to move clusters in the Windows NT 4.0 kernel, [4] which worked for both NTFS and FAT partitions. However, Windows NT 4.0 did not provide a graphical or command-line user interface. [4]
Disk Defragmenter first shipped as part of Windows 95 and later shipped with Windows 98 and Windows Me, licensed from Symantec Corporation. It could be scheduled using a Maintenance Wizard and supported command line switches. [5] In the version of Disk Defragmenter included with Windows 95 and 98, if the contents of the drive changed during defragmentation, the program paused, rescanned the entire drive, and then resumed the process from where it had left off. [6] This quirk was removed in the Windows Me version of Disk Defragmenter.
Disk Defragmenter in Windows 2000 was a stripped-down version of Diskeeper, licensed from Diskeeper Corporation. It uses the following techniques: [4]
In Windows 2000 and later operating systems, Microsoft Drive Optimizer has the following limitations:
In addition, the Windows 2000 version has the following limitations which were removed in Windows XP: [8]
Windows Disk Defragmenter was updated to alleviate some restrictions. [9] 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, [10] 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. [11] Windows XP and later has introduced Boot Files Defragment function, this function is enabled by default and can be disabled in Registry. [12]
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. [13] 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. [14] 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. [15] Notably, the Windows Vista defragmenter is much more effective than the version included with XP. [16]
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[ verification needed ] 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, Microsoft Drive Optimizer is also responsible for performing the TRIM command on SSDs. [17]
New Technology File System (NTFS) is a proprietary journaling file system developed by Microsoft. Starting with Windows NT 3.1, it is the default file system of the Windows NT family. It superseded File Allocation Table (FAT) as the preferred filesystem on Windows and is supported in Linux and BSD as well. NTFS reading and writing support is provided using a free and open-source kernel implementation known as NTFS3 in Linux and the NTFS-3G driver in BSD. By using the convert
command, Windows can convert FAT32/16/12 into NTFS without the need to rewrite all files. NTFS uses several files typically hidden from the user to store metadata about other files stored on the drive which can help improve speed and performance when reading data. Unlike FAT and High Performance File System (HPFS), NTFS supports access control lists (ACLs), filesystem encryption, transparent compression, sparse files and file system journaling. NTFS also supports shadow copy to allow backups of a system while it is running, but the functionality of the shadow copies varies between different versions of Windows.
In the maintenance of file systems, defragmentation is a process that reduces the degree of fragmentation. It does this by physically organizing the contents of the mass storage device used to store files into the smallest number of contiguous regions. It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmentation utilities try to keep smaller files within a single directory together, as they are often accessed in sequence.
Norton Utilities is a utility software suite designed to help analyze, configure, optimize and maintain a computer. The latest version of the original series of Norton Utilities is Norton Utilities 16 for Windows XP/Vista/7/8 was released 26 October 2012.
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.
In computing, CHKDSK
is a system tool and command in DOS, Digital Research FlexOS, IBM/Toshiba 4690 OS, IBM OS/2, Microsoft Windows and related operating systems. It verifies the file system integrity of a volume and attempts to fix logical file system errors. It is similar to the fsck
command in Unix and similar to Microsoft ScanDisk, which co-existed with CHKDSK
in Windows 9x and MS-DOS 6.x.
Diskeeper is a discontinued defragmentation app, 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. The final version of Diskeeper was released in March 2020. All of Diskeeper's features and functionality are now included in Condusiv's data performance software DymaxIO.
The Prefetcher is a component of Microsoft Windows which was introduced in Windows XP. It is a component of the Memory Manager that can speed up the Windows boot process and shorten the amount of time it takes to start up programs. It accomplishes this by caching files that are needed by an application to RAM as the application is launched, thus consolidating disk reads and reducing disk seeks. This feature was covered by US patent 6,633,968.
Contig is a command line defragmentation utility for Windows developed by Microsoft as part of the Sysinternals Suite.
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 negatively impacts seek time in spinning storage media, which is known to hinder throughput. Fragmentation can be remedied by re-organizing files and free space back into contiguous areas, a process called defragmentation.
NTBackup is the first built-in backup utility of the Windows NT family. It was introduced with Windows NT 3.51. NTBackup comprises a GUI (wizard-style) and a command-line utility to create, customize, and manage backups. It takes advantage of Shadow Copy and Task Scheduler. NTBackup stores backups in the BKF file format on external sources, e.g., floppy disks, hard drives, tape drives, and Zip drives. When used with tape drives, NTBackup uses the Microsoft Tape Format (MTF), which is also used by BackupAssist, Backup Exec, and Veeam Backup & Replication and is compatible with BKF.
Windows Vista contains a range of new technologies and features that are intended to help network administrators and power users better manage their systems. Notable changes include a complete replacement of both the Windows Setup and the Windows startup processes, completely rewritten deployment mechanisms, new diagnostic and health monitoring tools such as random access memory diagnostic program, support for per-application Remote Desktop sessions, a completely new Task Scheduler, and a range of new Group Policy settings covering many of the features new to Windows Vista. Subsystem for UNIX Applications, which provides a POSIX-compatible environment is also introduced.
Condusiv Technologies is an American software company based in Burbank, California. The company was formerly known as Diskeeper Corporation, a name derived from its flagship product, Diskeeper, a file-system defragmentation software package for Microsoft Windows and OpenVMS. Before adopting the Diskeeper name, the company was known as Executive Software International, Inc.
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 NT 4.0, 2000, XP, Vista, 7, 8, 8.1, 10, 11, Server 2003, 2008, 2008 R2, 2012, 2012 R2, 2016, 2019 and 2022.
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.
Defraggler is a freemium defragmentation utility developed by Piriform Software, which can defragment individual files or groups of files on computer memory systems. 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 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 is a free open-source disk defragmenting utility computer program for Windows. It was developed by Jeroen Kessels beginning in 2004 and was released under the GNU General Public License. Since version 4 of 2008, much changed from previous versions, JkDefrag was renamed MyDefrag by its developer; earlier JkDefrag versions continued to be available. MyDefrag, which was closed source freeware, was discontinued, with the last version being v4.3.1, file date 21 May 2010; for several years the MyDefrag website has been a redirect to the still-existing JkDefrag site, but links to downloadable JKdefrag files are dead. JkDefrag source code is still available from 3rd party websites
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:
PerfectDisk is a defragmentation software product for Windows developed by Raxco.