NTFS System Files

NTFS includes several system files, all of which are hidden from view on the NTFS volume. A system file is one used by the file system to store its metadata and to implement the file system. System files are placed on the volume by the Format utility.

Metadata Stored in the Master File Table

System File

File Name

MFT Record

Purpose of the File

Master file table $Mft 0

Contains one base file record for each file and folder on an NTFS volume. If the allocation information for a file or folder is too large to fit within a single record, other file records are allocated as well.

Master file table 2 $MftMirr 1

A duplicate image of the first four records of the MFT. This file guarantees access to the MFT in case of a single-sector failure.

Log file $LogFile 2

Contains a list of transaction steps used for NTFS recoverability. Log file size depends on the volume size and can be as large as 4 MB. It is used by Windows NT/2000 to restore consistency to NTFS after a system failure.

Volume $Volume 3

Contains information about the volume, such as the volume label and the volume version.

Attribute definitions $AttrDef 4

A table of attribute names, numbers, and descriptions.

Root file name index $ 5

The root folder.

Cluster bitmap $Bitmap 6

A representation of the volume showing which clusters are in use.

Boot sector $Boot 7

Includes the BPB used to mount the volume and additional bootstrap loader code used if the volume is bootable.

Bad cluster file $BadClus 8

Contains bad clusters for the volume.

Security file $Secure 9

Contains unique security descriptors for all files within a volume.

Upcase table $Upcase 10

Converts lowercase characters to matching Unicode uppercase characters.

NTFS extension file $Extend 11

Used for various optional extensions such as quotas, reparse point data, and object identifiers.

    12-15

Reserved for future use.

Quota management file $Quota 24

Contains user assigned quota limits on the volume space.

Object Id file $ObjId 25

Contains file object IDs.

Reparse point file $Reparse 26

This file contains information about files and folders on the volume include reparse point data.

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