Managing filesystem types

The dosfs filesystem type

The dosfs filesystem type allows users access to DOS-formatted floppies using regular system commands and system calls, just as with other filesystem types such as s5 or ufs. The ``dosfs filesystem layout'' figure shows the dosfs filesystem layout.

dosfs filesystem layout

UnixWare supports the FAT12, FAT16, VFAT, and FAT32 versions of the DOS filesystem type. The FAT12 and FAT16 versions come with DOS versions up to MS-DOS 6.x, and limit filenames to a traditional 8.3 style (an 8 character ``name'' portion and a 3 character ``extension'' portion). Only numeric and uppercase alpha characters are allowed, and the following special characters cannot be used:

   [space] " / [ ] : * < > | + = ; ' ? .

The version of dosfs known as ``Extended FAT'' or ``VFAT'', is essentially the same as the older versions of the dosfs, but removes some of the file naming restrictions. A VFAT filename can be 255 characters long, and can include lowercase alpha characters, any Unicode character, and spaces. Filenames can contain a dot (.), but cannot start with one. Nor can filesnames contain the following special characters:

   " / : * < > | ?

The rules for file names are the same in the FAT32 version of dosfs, and in addition it improves on the performance of the earlier versions of the filesystem in the following ways:

The dosfs filesystem type, whichever version you have using, does not support UNIX special files like pipes and block/character specials, nor does it support real or symbolic links.

© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 22 April 2004