Direct Access Storage Device

MeaningDirect Access Storage Device, or DASD, is a name that was coined buy IBM, for the conventional storage devices in computer systems, such as hard disk drives, magnetic drums, and data cells. Later, this term was also extended to mean optical disc drives and flash memory units.

The Direct Access Storage Device is a secondary storage device in which each physical record has a discrete location and a unique address.

A record on a Direct Access Storage Device can be accessed without having to read through any of the intermediate records from the current location.

The DASD storage class includes both fixed and removable media.

In case of removable storage devices, the user can remove them from the system at any given point of time, as long as he/she unmount the same, before hand.

Example of usage“A fixed storage device is any storage device defined during system configuration to be an integral part of the system DASD.”