Microsoft KB Archive/65777

INF: OS/2 SDK: Purpose of Volume Serial Number PSS ID Number: Q65777 Article last modified on 09-12-1991 PSS database name: O_Os2SDK

1.21 1.30

OS/2

Summary:

The volume serial number is a unique 32-bit number used by OS/2 to “positively” identify its hard disk/floppy disk volumes. It allows OS/2 to provide a volume ID that is more unique than the Label+CreationTime combination.

The OS/2 hard error handler will prompt the user for a removable hard disk/floppy disk that is not mounted by displaying both the volume serial number (as an 8-digit hexadecimal number) and the volume label. If there is no volume serial number on the hard disk/floppy disk, the volume serial number information will be returned as binary zeros. If there is no volume label on the hard disk/floppy disk, the volume label information will be returned as blank spaces. If there is no volume serial number and/or volume label for hard disk/floppy disk volumes formatted by MS-DOS versions 3.x, this information is not displayed by the hard error handler.

Currently, this feature is not a critical part of OS/2’s file system. However, as this feature becomes more important to OS/2 (perhaps for a future object-oriented file system, including added support for large capacity, removable volumes), it is possible that users may need to format floppy disks specifically for OS/2 if they want to take advantage of added OS/2 features.

For more information on the problem of media volume management in OS/2, please see pages 198-202 of Gordon Letwin’s “Inside OS/2” (Microsoft Press, 1988).

Copyright Microsoft Corporation 1991.