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Fsutil behavior

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Applies To: Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows 8.1, Windows Server 2003 R2, Windows Server 2008 R2, Windows Server 2000, Windows Server 2012 R2, Windows Server 2012, Windows 8

Queries or sets NTFS volume behavior, which includes:

  • The creation of 8.3 character-length file names

  • Extended character use in 8.3 character-length short file names on NTFS volumes

  • The updating of the Last Access Time stamp when directories are listed on NTFS volumes

  • The frequency with which quota events are written to the system log and to NTFS paged pool and NTFS non-paged pool memory cache levels

  • The size of the master file table zone (MFT Zone)

  • Silent deletion of data when the system encounters corruption on an NTFS volume.

  • File-delete notification (also known as trim or unmap)

For examples of how to use this command, see Examples.

Syntax

fsutil behavior query {allowextchar | bugcheckoncorrupt | disable8dot3 [<VolumePath>] | disablecompression | disableencryption | disablelastaccess | encryptpagingfile | mftzone | memoryusage | quotanotify | symlinkevaluation | disabledeletenotify}
fsutil behavior set {allowextchar {1|0} | bugcheckoncorrupt {1|0} | disable8dot3 [ <Value> | [<VolumePath> {1|0}] ] | disablecompression {1|0} | disableencryption {1|0} | disablelastaccess {1|0} | encryppagingfile {1|0} | mftzone <Value> | memoryusage <Value> | quotanotify <Frequency> | symlinkevaluation <SymbolicLinkType> | disabledeletenotify {1|0}}

Parameters

Parameter

Description

query

Queries the file system behavior parameters.

set

Changes the file system behavior parameters.

allowextchar {1|0}

Allows (1) or disallows (0) characters from the extended character set (including diacritic characters) to be used in 8.3 character-length short file names on NTFS volumes.

You must reboot your computer for this parameter to take effect.

Bugcheckoncorrupt {1|0}

Allows (1) or disallows (0) generation of a bug check when there is corruption on an NTFS volume. This feature can be used to prevent NTFS from silently deleting data when used with the Self-Healing NTFS feature.

You must reboot your computer for this parameter to take effect.

This parameter applies to: Windows Server 2008 R2 and Windows 7.

disable8dot3 [<VolumePath>] {1|0}

Disables (1) or enables (0) the creation of 8.3 character-length file names on FAT- and NTFS-formatted volumes. Optionally, prefix with the VolumePath specified as a drive name followed by a colon or GUID.

disablecompression {1|0}

Disables (1) or enables (0) NTFS compression.

You must reboot your computer for this parameter to take effect.

disableencryption {1|0}

Disables (1) or enables (0) the encryption of folders and files on NTFS volumes.

You must reboot your computer for this parameter to take effect.

disablelastaccess {1|0}

Disables (1) or enables (0) updates to the Last Access Time stamp on each directory when directories are listed on an NTFS volume.

You must reboot your computer for this parameter to take effect.

encryppagingfile {1|0}

Encrypts (1) or does not encrypt (0) the memory paging file in the Windows operating system.

You must reboot your computer for this parameter to take effect.

mftzone <Value>

Sets the size of the MFT Zone, and is expressed as a multiple of 200MB units. Set Value to a number from 1 (default is 200 MB) to 4 (maximum is 800 MB).

You must reboot your computer for this parameter to take effect.

memoryusage <Value>

Configures the internal cache levels of NTFS paged-pool memory and NTFS nonpaged-pool memory. Set to 1 or 2. When set to 1 (the default), NTFS uses the default amount of paged-pool memory. When set to 2, NTFS increases the size of its lookaside lists and memory thresholds. (A lookaside list is a pool of fixed-size memory buffers that the kernel and device drivers create as private memory caches for file system operations, such as reading a file.)

You must reboot your computer for this parameter to take effect.

quotanotify <Frequency>

Configures how frequently NTFS quota violations are reported in the system log. Valid values for are in the range 0 – 4294967295. The default frequency is 3600 seconds (one hour).

You must reboot your computer for this parameter to take effect.

symlinkevaluation <SymbolicLinkType>

Controls the kind of symbolic links that can be created on a computer. Valid choices are:

  1. Local to local symbolic links, L2L:{0|1}

  2. Local to remote symbolic links, L2R:{0|1}

  3. Remote to local symbolic links, R2R:{0|1}

  4. Remote to remote symbolic links, R2L:{0|1}

DisableDeleteNotify

Disables (1) or enables (0) delete notifications (for all volumes. Delete notification (also known as trim or unmap) is a feature that notifies the underlying storage device of clusters that have been freed due to a file delete operation. In addition:

  • Trim is enabled by default unless an administrator disables it. If your hard disk drive or SAN reports that it does not support trim, then your hard disk drive and SANs will not get trim notifications.

  • Enabling or disabling does not require a restart.

  • Trim is effective when the next unmap command is issued.

  • Existing inflight IO are not impacted by the registry change.

  • Does not require any service restart when you enable or disable trim.

This parameter was introduced in Windows Server 2008 R2 and Windows 7.

Remarks

  • The MFT Zone is a reserved area that enables the master file table (MFT) to expand as needed to prevent MFT fragmentation. If the average file size on the volume is 2 KB or less, it can be beneficial to set the mftzone value to 2. If the average file size on the volume is 1 KB or less, it can be beneficial to set the mftzone value to 4.

  • When disable8dot3 is set to 0, every time you create a file with a long file name, NTFS creates a second file entry that has an 8.3 character-length file name. When NTFS creates files in a directory, it must look up the 8.3 character-length file names that are associated with the long file names. This parameter updates the HKLM\SYSTEM\CurrentControlSet\Control\FileSystem\NtfsDisable8dot3NameCreation registry key.

  • The allowextchar parameter updates the HKLM\SYSTEM\CurrentControlSet\Control\FileSystem\NtfsAllowExtendedCharacterIn8dot3Name registry key.

    The disablelastaccess parameter reduces the impact of logging updates to the Last Access Time stamp on files and directories. Disabling the Last Access Time feature improves the speed of file and directory access. This parameter updates the HKLM\SYSTEM\CurrentControlSet\Control\FileSystem\NtfsDisableLastAccessUpdate registry key.

    Notes:

    • File-based Last Access Time queries are accurate even if all on-disk values are not current. NTFS returns the correct value on queries because the accurate value is stored in memory.

    • One hour is the maximum amount of time that NTFS defers updating Last Access Time on disk. If NTFS updates other file attributes such as Last Modify Time, and a Last Access Time update is pending, NTFS updates Last Access Time with the other updates without additional performance impact.

    • The disablelastaccess parameter can affect programs such as Backup and Remote Storage that rely on this feature.

  • Increasing physical memory does not always increase the amount of paged pool memory available to NTFS. Setting memoryusage to 2 raises the limit of paged pool memory. This might improve performance if your system is opening and closing many files in the same file set and is not already using large amounts of system memory for other applications or for cache memory. If your computer is already using large amounts of system memory for other applications or for cache memory, increasing the limit of NTFS paged and non-paged pool memory reduces the available pool memory for other processes. This might reduce overall system performance. This parameter updates the HKLM\SYSTEM\CurrentControlSet\Control\FileSystem\NtfsMemoryUsage registry key.

  • The value specified in the mftzone parameter is an approximation of the initial size of the MFT plus the MFT Zone on a new volume, and it is set at mount time for each file system. As space on the volume is used, NTFS adjusts the space reserved for future MFT growth. If the MFT Zone is already large, the full MFT Zone size is not reserved again. Because the MFT Zone is based on the contiguous range past the end of the MFT, it shrinks as the space is used.

    The file system does not determine the new MFT Zone location until the current MFT Zone is completely used. Note that this never occurs on a typical system.

  • Some devices may experience performance degradation when the delete notification feature is turned on. In this case, use the disabledeletenotify option to turn off the notification feature.

Examples

To query for the disable 8dot3 name behavior for a disk volume specified with the GUID, {928842df-5a01-11de-a85c-806e6f6e6963}, type:

fsutil behavior query disable8dot3 Volume{928842df-5a01-11de-a85c-806e6f6e6963}

You can also query the 8dot3 name behavior by using the 8dot3name subcommand.

To query the system to see if TRIM is enabled or not, type:

PS C:\windows\system32> fsutil behavior query DisableDeleteNotify
DisableDeleteNotify = 0

To set TRIM (disabledeletenotify), type

PS C:\windows\system32> fsutil behavior set DisableDeleteNotify 1
DisableDeleteNotify = 1

Additional references

Command-Line Syntax Key

Fsutil

Fsutil 8dot3name