## Storage Device Driver Reference

[prev][next][parent][TOC]

### OS2DASD.DMD - Technical Reference

The OS2DASD Device Manager (OS2DASD.DMD) provides the interface between the OS/2 File Systems (FAT, HPFS) and Adapter Drivers (*.ADDs) that support fixed and removable magnetic disks.

This device manager allows the *.ADD drivers to communicate with adapter or disk hardware without interacting with the logical contents of these devices or being affected by the complexity of OS/2 block device driver interfaces. The device manager communicates with *.ADD drivers exclusively by way of Input/Output Request Blocks (IORBs), as described in the preceding chapters of the Storage Device Driver Reference.

The primary functions of this device manager are:

1.Implementing the OS/2 Kernel/FileSystem block device driver interfaces; creating IORBs as required for communication to .ADD drivers.

2.Scanning .ADD drivers for removable or fixed magnetic devices.

3.Managing partitioned devices by creating logical drives for partitioned disks and reporting these logical drives to the OS/2 kernel.

4.Providing IOCtl interfaces to the file system utility applications to allow for the preparation of the media.

5.Providing for the attachment from a set of logical drives to a physical removable device is called pseudo drive support. An example is the mapping of drive A: or B: to a single diskette drive.