Abstract: A method, system, and computer program product for protecting data of a shared access data storage system from being overwritten, where the data storage system includes a device which is shared by separate hosts over at least two logically or physically distinct communication paths. An overwrite protection facility operates the data storage system controller processor independently of the hosts to automatically protect the device upon the occurrence of a write command for the device. The protection allows only the communication path issuing the write command, and communication paths in the same group as the issuing communication path, to issue commands resulting in movement of the media on the device. Commands not resulting in movement of the media are allowed from any communication path. The protection continues until specifically released by a “MEDIA REMOVAL” command. The protection, in one embodiment, is by means of a prime protected attribute for the device-communication path pair.

Abstract: A generic device driver simulator having the knowledge of the device specific behavior moved out of simulator program code is disclosed. The generic device driver simulator includes a generic device driver for supporting application functions without device specific coding included therein, a database including device specific models of device drivers supported by the generic device driver and an interpreter for controlling the generic device driver according to the definitions of functions and data structures in the database. The generic device driver simulator also includes a watcher for defining watchpoints, the watchpoints identifying types of calls from the application. The watcher displays information when a watchpoint is triggered by a call from the application. The interpreter includes an input script for each device function or for multiple device functions that are supported by the generic device driver.