Features Unique to NTFS

This section describes NTFS functionality that is not supported by the FAT file system.

Multiple Data Streams

The NTFS file system supports multiple data streams. The stream name identifies a new data attribute on the file. Streams have separate opportunistic locks, file locks, allocation sizes, and file sizes, but sharing is per file.

The following is an example of an alternate stream:

myfile.dat:stream2

This feature permits related data to be managed as a single unit. For example, Macintosh computers use this type of structure to manage resource and data forks. Or, a company might create a program to keep a list of changes to the file in an alternate stream, thus keeping archive information with the current version of the file.

As another example, a library of files might exist where the files are defined as alternate streams, as in the following example:

library:file1
       :file2
       :file3

You could use a smart compiler to create a file structure like the following example:

program:source_file
       :doc_file
       :object_file
       :executable_file

You can use the Win32 API CreateFile to create an alternate data stream. Or, from the command prompt, you can enter commands such as:

echo text>program:source_file
more <program:source_file

Note

Because the NTFS file system is not supported on floppy disks, when you copy an NTFS file to a floppy disk, data streams and other attributes not supported by the FAT file system are lost.