Storage Technology Corporation

International Business Machines Corporation

David Grant Beal

Christopher James West

Michael Steven Milillo

Fletcher L Hill

Nancy R Jurestovsky

Scott Adam States

Michael R Stephens

Charles Allen Milligan

George A Rudeseal

Theresa Lynn Segura

David Glenn Hostetter

Henry S Ludlam

Peter H Tallman

Fred C Eifert

Paul R Swiatek

JoEtta S Chikira

Jo Etta Hill

A method and system for retrieving data that is stored on a backup or secondary storage system located at a remote location to a local storage system. Restoring of backup data involves the transferring of a point-in-time copy of primary system data from a secondary storage system to the local system. The point-in-time copy is created on the secondary system using an asynchronous remote copy scheme. The point-in-time copy that is restored may be either an entire volume or portions thereof.

Storage control system for restoring a remote data copy

A data structure, method, and computer system for fast data copy is provided which uses control structures in a data copy track table. The control structures include a physical location pointer, a physical location pointer flag, a forward track pointer and a backward source pointer. These control structures are used in an update-in-place architecture. Requests for source or target data updates do not require additional write cycles.

Fast data copy using a data copy track table

System and method for restoring data from secondary volume to primary volume in a data storage system

A method and apparatus for transferring data from a first storage system to a second storage system in which the first storage system includes a first plurality of storage devices and the second storage system includes a second plurality of storage devices. Data is transferred using a pair of devices selected for transferring data for all of the storage devices. Data to be transferred from source storage devices within the first plurality of storage devices is placed or queued on a selected primary storage device within the first plurality of storage devices. The data is sent to a selected secondary storage device within the plurality of storage devices. The data is relocated from the selected secondary storage device to target storage devices within the second plurality of storage devices.

Method and apparatus for transferring data between a primary storage system and a secondary storage system using a bridge volume

A storage control system and method for storing and retrieving data to and from a tape backup system that is located remotely from a primary host system. The primary system is coupled to a remote storage system for remote copy applications. The tape backup system is coupled to the remote storage system and operated at the remote site. Conducting control signals through the primary storage controller to the remote storage controller enables control over the tape backup system from the local or primary site. Data can be backed up to the tape system from the remote storage site which enables the local host to perform applications during the backup window. Data can also be restored from the tape system to the remote storage system and transferred back to the primary system via the communications link.

Storing and retrieving data on tape backup system located at remote storage system site

The present invention relates to a method for testing the operability of a Peer to Peer Remote Copy (PPRC) data storage system in disaster situations. A PPRC data storage system includes a host processor, a primary storage subsystem and a secondary storage subsystem where the secondary storage subsystem is coupled to the primary storage subsystem for mirroring of data therebetween. A command is sent from the host processor directing the primary storage subsystem to simulate a disaster. Upon detection of the disaster, the host establishes direct communication with the secondary storage subsystem, and validates the integrity of the system by comparing data from the secondary storage subsystem to data from the primary storage subsystem.

System and method for simulating disaster situations on peer to peer remote copy machines

A data storage system including first, second, third and fourth virtual storage volumes, the first and second virtual storage volumes controlled to enable a mirroring and synchronization of data therebetween. The data storage system further includes a first processor that is responsive to a &ldquo;copy pair&rdquo; command or its equivalent to copy a directory from the first virtual storage volume to a directory of the third virtual storage volume. The first processor also dispatches a copy command, or its equivalent, to copy the directory of the second virtual storage volume to the directory of the fourth storage volume. A second processor is responsive to the copy command to cause a copying of the directory of the second virtual storage volume to the directory of the fourth virtual storage volume. Thus, the third and fourth virtual storage volumes are controlled to include directories which duplicate directories of the first and second virtual storage volumes.

System and method for enabling pair-pair remote copy storage volumes to mirror data in another pair of storage volumes

A data storage system includes at least first, second and third virtual storage volumes, the second and third virtual storage volumes being remotely coupled as a PPRC pair to enable a mirroring of data therebetween. The storage system is responsive to a snapshot command from a host processor, to cause transfer of the directory of the first virtual storage volume to the second virtual storage volume. The storage system then invokes a PPRC mirroring procedure which (i) detects an unsynchronized condition between the second and third virtual storage volumes (upon transfer of the directory from the first virtual storage volume to the second virtual storage volume), and (ii) causes a transfer of data, pointed to by the transferred directory, to the third virtual storage volume, until the second and third virtual storage volumes are again in synchronism. This action achieves a synchronization of the first and third virtual storage volumes, while the first virtual storage volume is relieved from certain processing overhead incident to transfer of data to the remotely located third virtual storage volume.

System and method for enabling pair-pair remote copy storage volumes to mirror data in another storage volume

A method and system for the automatic data recovery for a duplex pair is provided. The preferred embodiment includes the discovery of lost data on the first subsystem. A copy of the lost data is automatically transferred from the second subsystem to the first subsystem. Then the copy of the lost data is automatically written into the first subsystem. The host processor and the operator is unaware data had been lost. The method and system of the present invention eliminates the need to terminate the job which triggered the discovery of the lost data. It also eliminates the need for any involvement of the operator in the data recovery process.

Automatic data recovery for a duplex pair

Copies of data that are stored on tracks of a primary disk volume and a backup disk volume are synchronized by a method which reduces the amount of data that is transferred. The primary disk volume includes tracks with current data (i.e., non-empty tracks) and tracks with no current data (i.e., empty tracks). The method transfers to the backup disk volume only data from non-empty tracks on the primary disk volume and then writes the data onto tracks in the backup disk volume that correspond to the non-empty tracks of the primary disk volume. Prior to writing of the data onto the backup disk volume, it is preferred that the backup disk volume have all tracks erased so that after the write action, only the tracks with current data have data written therein. Further, at the primary disk volume, only tracks having current data are read. Accordingly, substantial savings in processing and data transfer times are achieved.

Synchronization of shared data stores through use of non-empty track

The knowledge based system identifies the occurrence of a failure within the customer equipment and functions using its rules, hypotheses and collected data to isolate the functional resource which is the source of the error in the customer equipment and, whenever possible, 'fence' or isolate the failed functional resource that has caused the error. In addition, the knowledge based system makes use of resource related rules to remove a resource or set of resources available for concurrent other failure management operations. The resource related rules allow resources to function in any one non-operational or operational mode or to functional simultaneously in multiple non-operational modes.

Knowledge based resource management

The knowledge based system functions in a machine initiated maintenance environment to provide efficient and timely maintenance of customer equipment. The knowledge based system provides the failure evaluation function through the use of an expert or knowledge based system that is installed in the customer equipment. The knowledge based system makes use of a set of rules and hypotheses to operate on data collected from various points within the customer equipment to monitor the operational integrity of the customer equipment. This knowledge based system identifies the occurrence of a failure within the customer equipment and functions using its rules, hypotheses and collected data to isolate the source of the error in the customer equipment and, whenever possible, 'fence' or isolate the failed field replaceable unit that has caused the error.

Knowledge based machine initiated maintenance system

A disk storage system that writes multiple copies of records directed to user-specified volumes. A plurality of spaced apart control units interconnected by direct data links and a corresponding plurality of sets of recording means communicate over the direct data links when a write request is received by one control unit to cause one volume in each set of recording means to write a copy of the received record.

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Longmont, CO, United States of America

David Grant Beal