Automatic Configuration in a Multi-Adapter Environment
Original Publication Date: 1988-Feb-01
Included in the Prior Art Database: 2005-Feb-14
This article describes a technique which allows a system with an existing ST506/412 (a type of hard disk interface) disk subsystem to be substantially upgraded by adding an enhanced small device interface (ESDI) disk subsystem without having to remove the ST506/412 subsystem. ESDI drives provide greater storage capacity than has been previously available with other technologies. Coexistence of a ST506/412 attachment and an ESDI attachment is achieved through software maintenance of the disk subsystem environment. A design point for support of coexistence is that when ESDI is alone in the box no performance loss would occur. This loss would occur due to the added overhead built into the code to support coexistence. A number of items need to be managed in order to support ESDI disk and ST506/412 disk coexistence.