International Business Machines Corporation

Dale Arthur Legband

Michael Norman Day

Daniel Charles Wolfe

Wade David Shaw

Daniel Quinto Bandera

Donald Edwin Wood

Ashok Kakkunje Adiga

Scott Lyon Porter

Ralph John Gerlach

Kenneth Adam Kalinoski

A hot spare drive within a disk array mirrors writes to a selected drive within the disk array. The mirror is light weight in that little effect on system performance is seen, since both writes need not be complete before the write is returned as successful. Upon subsequent failure of a drive within the array, the need for data regeneration is reduced or eliminated if the failed drive is the mirrored drive. The hot spare remains available for failure recovery when a different drive (other than the mirrored drive) fails, in which case conventional data regeneration techniques may be employed. When the mirrored drive fails, however, the period during which the disk array operates with diminished performance is reduced since data from the failed drive is available on the hot spare and regeneration is only required for data not completely mirrored. Even when a drive is arbitrarily selected within the array for mirroring, an overall reduction in the time required for data regeneration of failed disks will be seen in systems employing large numbers of arrays. Error information relating to the disk drives within the drive array and/or predictive failure analysis may be employed to increase the probability that the failed drive was mirrored. The prospect of complete data loss due to multiple drive failure is also reduced, since multiple drive failure is not fatal if one of the failed drives was mirrored.

Hot spare light weight mirror for raid system

A method and system for autoconfiguring redundant arrays of memory storage devices contained within receptacles having one or more slots containing hardware sufficient to accept and electrically communicate with such memory storage devices. The capacities of the memory storage device receptacles for accepting memory storage devices are determined, and used to define an initial positioning of devices in at least one memory storage device receptacle. One or more asymmetrical groupings of memory storage devices is defined to permit an equation of electrically detected relative positions of the memory storage devices with actual physical positions within the receptacle. Thereafter, additional devices are added into the receptacles such that the ability to equate electrically detected relative positions of the devices with physical positions is preserved.

Method and system for automatically configuring redundant arrays of disk

In order to increase the number of datastreams provided by a multimedia system, a cluster of clusters of multimedia A/V server subsystems is provided. Each cluster in turn is comprised of a plurality of A/V servers, a shared loop architecture plurality of data storage devices interconnected to the A/V servers whereby any storage device is substantially equally accessible by any of the servers in the cluster; and a highly available control server subsystem interconnected to the A/V servers and the data storage devices for controlling the A/V servers and the data storage devices. Each of the clusters is interconnected to a high speed switch for delivery of datastreams from the cluster to the end user. One of the control server subsystems also serves as a master control server assigning a request for a datastream to one of the clusters.

System and method for datastreams employing shared loop architecture

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Pflugerville, TX, United States of America

Dale Arthur Legband