Storage Technology Corporation

International Business Machines Corporation

David Glenn Hostetter

Michael Steven Milillo

Christopher James West

Robert P Eskenberry

Jennifer Johnson

John Timothy O'Brien

David Grant Beal

Theresa Lynn Segura

Michael Richard Crater

Scott Adam States

Peter H Tallman

Steven Christopher Fraioli

Michael S Kelly

Chrisopher J West

Brad David Privratsky

A cache storage system and method are provided for saving storage space in a cache, the system and method for use in a data storage system having multiple storage devices and multiple virtual addresses, each virtual address having a data object associated therewith. Each data object is stored at a storage device location having a unique identifier. The cache storage system and method include a cache for storing a data object associated with at least one virtual address. For a first virtual address, the first virtual address data object is staged into the cache. For a second virtual address, a pointer is generated for use in pointing to the first virtual address data object staged in the cache when the storage device location identifier of the second virtual address data object matches the storage device location identifier of the first virtual address data object.

Cache storage system and method

A system and method for synchronizing a data copy that include a source volume having a data file stored thereon, the source volume for receiving write commands from a host, executing the write commands to generate an updated data file, and generating a record of the write commands. The system and method further include a secondary volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the write command record, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file.

System and method for synchronizing a data copy using an accumulation remote copy trio

A system and method for synchronizing a data copy include in one embodiment first and second remote copy trios, each with source, target, and secondary volumes. Source volumes store initial data files, execute write commands to generate updated data files, and generate records of the write commands. Target volumes receive copies of the initial data files and the write command records, and transmit the copies of the initial data files and data indicated by the write command records to secondary volumes. Secondary volumes store the copies of the initial data files and the data indicated by the write command records, which are available for use in generating copies of the updated data files. The target volumes transmit to the secondary volumes in series relative to each other so that consistency is maintained at all times across the source volumes.

System and method for synchronizing a data copy using an accumulation remote copy trio consistency group

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 method for use in a peer to peer remote copy (PPRC) system having primary and secondary storage systems to make data available from established PPRC storage volume pairs includes isolating the secondary storage system to be in a stand alone state such that access from any storage systems and hosts is prevented. It is then determined if each storage volume of the secondary storage system is part of an established PPRC storage volume pair. Each established PPRC storage volume pair is then terminated such that the storage volumes of the secondary storage system that are part of the established PPRC storage volume pairs are accessible to hosts. The secondary storage system is then made available to hosts to effect data recovery of the established PPRC storage volumes.

Automatic stand alone recovery for peer to peer remote copy (PPRC) operations

A method and apparatus in a data processing system for copying data. A request is received to copy data from a first storage system to second storage system, wherein the request identifies a source volume on the first storage system and a target volume on the second storage system and wherein data is located on a first source volume in the first storage system. Data is transferred to a second source volume in the first storage system. A pair is automatically established between the second source volume and the target volume. The data for the request is copied from the second source volume to the target volume after the pair has been automatically established. The pair is terminated after the data has been copied to the target volume. The requester originating the request is notified of the result of the copy operation.

Method and apparatus for copying data from one storage system to another storage system

A system and method for providing a trusted machine state in a data processing system is disclosed. The data processing system includes a memory. The trusted machine state is stored in a first portion of the memory. The method and system include saving the trusted machine state in a second portion of the memory and reinitializing a portion of the memory. The portion of memory is separate from the second of memory. The method and system further include restoring the trusted machine state in the memory. According to the method and system disclosed herein, the data processing system may recover from failures and resume operation. Moreover, a non-disruptive code load, in which a new program can be loaded without disrupting system operations, may be performed.

Method and system for providing a trusted machine state

A system incorporating the invention stores data on communicating disk drives in such a manner as to enable recovery of the data in the event a failure of one of the disk drives. The system includes a first disk drive and a second disk drive, both for storing compressed data records in compressed track formats. Each compressed data record includes a CRC value. A cache stores compressed tracks of data records that are read from the first disk drive and a CRC value is calculated for each stored track of compressed data records. That CRC value is appended to the compressed track. A switch is coupled between the cache, a host processor and the second disk drive for dispatching and receiving tracks of compressed data records between the first disk drive and the second disk drive. The switch includes computational circuitry for calculating a CRC value for each track of compressed data records received from the cache and for determining a match or non-match state with the CRC value appended to each track of compressed data records. In such manner, a system which is primarily adapted to handle records with appended CRC values is adapted to handle tracks of compressed data records with appended CRC values so as to assure data integrity.

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Boulder, CO, United States of America

David Glenn Hostetter