Abstract: A host connected outboard back-up and recovery system has a tape drive connected to a plural port solid-state cache memory which, in turn, is connected to a disk drive. Data to be backed-up can first be copied from the disk drive to the cache and then from the cache to the tape drive in back-up operations, so that the relative speeds of the disk drive and the tape need not be matched. An outboard controller controls flow of the data between the disk drive and the tape drive and additionally controls storage of the data on the tape, so that host computer involvement is avoided.

Abstract: A method for detection of a sequential data stream which can be performed in a data storge subsystem without host computer intervention is disclosed featuring examination of the channel program processed during a read operation for signals indicative that the data is not part of a sequential data stream, for example, embedded seek instructions. If a particular channel program for does not contain such indications, the successive record or records may then be staged to a faster access memory device such as a solid-state cache. The invention is described in a plug-compatible, software-transparent configuration.

Abstract: A method of operation of a memory array for storage of records of differing predetermined sizes is disclosed which features division of the array into domains which are substantially integral multiples of the predetermined record sizes. In a preferred embodiment the domain allocation may be varied adaptively in accordance with usage so as to enable more efficient use of the array.

Abstract: A buffered cache memory subsystem is disclosed which features a solid-state cache memory connected to a storage director which interfaces a host channel with a control module controlling operation of a long-term data storage device such as a disk drive. The solid-state cache memory is connected to plural directors which in turn may be connected to differing types of control modules, whereby the cache is usable with more than one type of long-term data storage means within a given system. The cache memory may be field-installed in a preexisting disk drive storage system and is software transparent to the host computer, while providing improvements in overall operating efficiency. In a preferred embodiment, data is only cached when it is expected to be the subject of a future host request.

Abstract: A method for detection of a sequential data stream which can be performed without host computer intervention is disclosed featuring examination of a data record and channel program during read operations for signals indicative that the data is not part of a sequential data stream, for example, embedded seek instructions. If a particular sought for record does not contain such indications, the successive record or records may then be staged to a faster access memory device such as a solid-state cache. The invention is described in a plug-compatible, software-transparent configuration.

Abstract: A method of operation of a memory array for storage of records of differing predetermined sizes is disclosed which features division of the array into domains which are substantially integral multiples of the predetermined record sizes. In a preferred embodiment the domain allocation may be varied adaptively in accordance with usage so as to enable more fully efficient use of the array.