5.3 NTFS Reserved File Names

NTFS uses a number of names as part of the file system internals. The names used by NTFS within the root directory are listed in the following table:

Filename	Description
\$Mft	Master File Table (MFT) - an index of every file
\$MftMirr	A backup copy of the first 4 records of the MFT
\$LogFile	Transactional logging file
\$Volume	Serial number, creation time, dirty flag
\$AttrDef	Attribute definitions
\$Bitmap	Contains the volume's cluster map (in-use vs. free)
\$Boot	Boot record of the volume
\$BadClus	Lists bad clusters on the volume
\$Secure	Security descriptors used by the volume
\$UpCase	Table of uppercase characters used for collating
\$Extend	A directory

An additional set of names are found in the system directory as follows:

Filename	Description
\$Extend\$Config	Use for NTFS repair activity
\$Extend\$Delete	Delete file name
\$Extend\$ObjId	Unique Ids given to every file
\$Extend\$Quota	Quota information
\$Extend\$Repair	Repair name
\$Extend\$Repair.log	Repair log name
\$Extend\$Reparse	Reparse point information
\$Extend\$RmMetadata	Transactional NTFS resource manager metadata name
\$Extend\$Tops	Transactional NTFS Old Page Stream, used to store data that has been overwritten inside a currently active transaction
\$Extend\$Txf	Transactional NTFS
\$Extend\$TxfLog	Transactional NTFS log