NTFS Documentation: $Bitmap
Definition
This is a system file that indicates which LCNs of the volume are used.
Layout
One bit for each LCN, starting at LCN 0. The bit is set when the LCN is used.
Interest
It increases the performance when searching for free space on the volume. It also makes easy to extend the volume: just extend this file.
Regis Duchesne at VIA, ECP, France
Last modified: Sun Feb 14 15:08:14 PST 1999