Method and system for concurrent access during backup copying of data

Claim 1

A method in a data processing system for permitting high concurrency of access to designated data storage in a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having a subsystem memory therein, wherein data is accessed by said data processing system from one of said plurality of storage devices utilizing one of a plurality of Unique Control Blocks (UCBs), each UCB identifying a selected one of said plurality of storage devices and permitting only one application to access said selected one of said plurality of storage devices at a time, and an associated data retrieval command sequence which identifies data to be accessed within said selected one of said plurality of storage devices, said method comprising the steps of: copying at least a portion of said designated data from a first one of said plurality of storage devices to said subsystem memory within said storage device control unit; selecting a UCB which identifies a second one of said plurality of storage devices; and associating a selected data retrieval command sequence with said selected UCB which identifies said second one of said plurality of storage devices, said selected data retrieval command sequence identifying said at least a portion of said designated data as located within said subsystem memory wherein other data within said first one of said plurality of storage devices may be concurrently accessed utilizing an alternate UCB.

Claim 2

A method in a data processing system for permitting high concurrency of access to designated data storage in a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having a subsystem memory therein, wherein data is accessed by said data processing system from one of said plurality of storage devices utilizing one of a plurality of Unique Control Blocks (UCBs), each UCB identifying a selected one of said plurality of storage devices and permitting only one application to access said selected one of said plurality of storage devices at a time, and an associated data retrieval command sequence which identifies data to be accessed within said selected one of said plurality of storage devices, said method comprising the steps of: copying at least a portion of said designated data from a first one of said plurality of storage devices to said subsystem memory within said storage device control unit; selecting a UCB which identifies a second one of said plurality of storage devices; and associating a selected data retrieval command sequence with said selected UCB which identifies said second one of said plurality of storage devices, said selected data retrieval command sequence identifying said at least a portion of said designated data as located within said subsystem memory wherein other data within said first one of said plurality of storage devices may be concurrently accessed utilizing an alternate UCB.

Claim 7

A method in a data processing system for permitting high concurrency of access to designated data stored in a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having a subsystem memory therein during backup copying thereof, wherein data is accessed by said data processing system from one of said plurality of storage devices utilizing one of a plurality of Unique Control Blocks (UCBs), each UCB identifying a selected one of said plurality of storage devices and permitting only one application to access said selected one of said plurality of storage devices at a time, and an associated data retrieval command sequence which identifies data to be accessed within said selected one of said plurality of storage devices, said method comprising the steps of: forming a data logical-to-physical storage system address concordance for said designated data; physically backing up a portion of said designated data within a first one of said plurality of storage devices on a scheduled or opportunistic basis by accessing and copying said portion of said designated data utilizing a first UCB which identifies said first one of said plurality of said storage devices; performing at said first one of said plurality of storage devices any application initiated updates to uncopied designated data by temporarily deferring said updates, writing sidefiles of said uncopied designated data which is affected by said updates to said subsystem memory and thereafter writing said updates to said first storage device; and accessing and copying said sidefiles by: selecting a UCB which identifies a second one of said plurality of storage devices; and associating a selected data retrieval command sequence with said selected UCB which identifies said second one of said plurality of storage devices, said selected data retrieval command sequence identifying said at least a portion of said designated data as located within said subsystem memory wherein other data within said first one of said plurality of storage devices may be concurrently accessed utilizing an alternate UCB.

Claim 8

A method in a data processing system for permitting high concurrency of access to designated data stored in a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having a subsystem memory therein during backup copying thereof, wherein data is accessed by said data processing system from one of said plurality of storage devices utilizing one of a plurality of Unique Control Blocks (UCBs), each UCB identifying a selected one of said plurality of storage devices and permitting only one application to access said selected one of said plurality of storage devices at a time, and an associated data retrieval command sequence which identifies data to be accessed within said selected one of said plurality of storage devices, said method comprising the steps of: forming a data logical-to-physical storage system address concordance for said designated data; physically backing up a portion of said designated data within a first one of said plurality of storage devices on a scheduled or opportunistic basis by accessing and copying said portion of said designated data utilizing a first UCB which identifies said first one of said plurality of said storage devices; performing at said first one of said plurality of storage devices any application initiated updates to uncopied designated data by temporarily deferring said updates, writing sidefiles of said uncopied designated data which is affected by said updates to said subsystem memory and thereafter writing said updates to said first storage device; and accessing and copying said sidefiles by: selecting a UCB which identifies a second one of said plurality of storage devices; and associating a selected data retrieval command sequence with said selected UCB which identifies said second one of said plurality of storage devices, said selected data retrieval command sequence identifying said at least a portion of said designated data as located within said subsystem memory wherein other data within said first one of said plurality of storage devices may be concurrently accessed utilizing an alternate UCB.