When you format a volume using NTFS, Windows creates a master file table MFT and metadata files. The MFT is a relational database that consists of rows of file records and columns of file attributes. It contains at least one entry for every file on an NTFS volume, including the MFT itself.
Small files less than about 1.5 KB are stored completely inside the MFT resulting in the optimal one I/O operation to access the complete file with all attributes.
To determine the current size of the MFT on a Microsoft Windows 2000-based computer, use Disk Defragmenter to analyze the NTFS drive, and then click View Report This displays the drive statistics, including the current MFT size and number of fragments.
Disk Defragmenter displays system files in green. They consists of
In Windows NT you can see the size of the MFT by using the command; dir /a $mft
Because the MFT stores information about itself, NTFS reserves the first records of the MFT for metadata files. Metadata file names begin with a $ as shown in the following table. The remaining records of the MFT contain the file and folder records for each file and folder on the volume.
Metadata Files Stored in the Master File Table
MFT Zone - Windows XP
To prevent the MFT from becoming fragmented, NTFS reserves 12.5 percent of volume by default for exclusive use of the MFT. This space, known as the MFT zone, is not used to store data unless the remainder of the volume becomes full.
Depending on the average file size and other variables, as the disk fills to capacity, either the MFT zone or the unreserved space on the disk becomes full first.
In either case, fragmentation of the MFT occurs when one region or the other becomes full. You can change the size of the MFT zone for newly created volumes by using the fsutil behavior set mftzone command. This command uses four settings, 1–4, which correspond to a percentage of the disk to be used as the MFT zone. The MFT zone sizes follow:
MFT Zone - Windows 2000
The default MFT Zone is calculated and reserved
by Ntfs.sys when it mounts the volume, and is based on volume size. You can
increase the MFT Zone by means of the registry entry documented below.
NOTE: This is a run-time parameter and does not affect the actual format of a volume. Rather, it affects the way NTFS allocates space on all volumes on a given system.