International Business Machines Corporation

Luis Felipe Cabrera

M Shannon Lietz

Robert Michael Rees

Inderpal Singh Narang

Chandrasekaran Mohan

Darrell D Long

Barry J Nisly

Claudia Beinglas Dragoescu

Leon Daniel Baranovsky

Chiehshow Chin

Henry Robert Coy

William Q Bonney

Christian Price

Brad A Rambur

Javier Godinez

Iii Neher Ted R

Jay Jiebing Yu

Matthew Sivertson

Vinay Kumar

Bojan Beran

Alex Balazs

In a database system with linkage between data in the database system and files in a system for filing data which is external to the database system (&ldquo;the filing system&rdquo;), backup and restoration of the database are coordinated with the filing system. Backup of a referenced file is initiated when the file is linked to the database system. The file backup is asynchronous to the linking process. When database backup occurs, all unfinished file backups are accelerated and completed before the database backup is declared successful. When a database is restored to a state with reference to files in a file manager, the database system causes the file manager to ensure that referenced files are linked to the database system.

Method and means for backup and restoration of a database system linked to a system for filing data

Extensions to a database system provide linkage between data in the database system and files in a system for filing data which is external to the database system ('the filing system'). The linkage includes an external file reference (efr) data type which is defined in the database system for reference to files that are stored in the filing system. When entries are made in the database system that include efr data-type references to files in the filing system, control information is provided by the database system to the filing system. The control information causes the filing system to control processing of referenced files according to referential constraints established in the database system.

Method and means for linking a database system with a system for filing

A method and apparatus that maintains in stable storage an identification of which copies in a mirrored disk system are currently up to date without requiring the use of a logging mechanism. The invention may include a plurality of mirrored disk drives and a processing unit for controlling the writing and reading of data units to and from mirrored disk drives, wherein the processing unit establishes and maintains cohort sets for each mirrored disk drive. The cohort set represents the status of copies of the data units stored on the mirrored disk drives and contains membership information for redundant copies of data units stored in the plurality of mirrored disk drives. The membership information comprises a data structure of 2n status bits for identifying which disks contain current copies of the data units, where n is the number of disks in the system, and wherein the first n bits are used to indicate an intention to update the membership information for the copies and the second n bits are used indicate a current state of the membership information. The data structure may further include log(n) additional bits for identifying each mirrored disk.

Method and apparatus for establishing and maintaining the status of

An apparatus, a method, and a computer program product conceptually provide a logical unit of undivided data storage that spans physical storage device boundaries. The apparatus manages the logical unit of undivided storage using metadata information stored on the physical storage devices. Advantageously, the apparatus replicates a minimum portion of the metadata information across all of the data storage devices and favors writing metadata only in the devices where the information is required to operate. In a preferred embodiment, a logical unit of undivided storage is created by defining a logical volume and allocating portions of available physical data storage devices thereto in order to provide a minimum logical volume size. Metadata is generated and stored on the data storage devices to provide detailed information about the portions of each data storage device that have been allocated to the logical volume. After initialization, the size of the logical volume can be automatically changed such that portions of the data storage devices are allocated to or deallocated from the logical volume. Following an allocation or deallocation operation, the metadata stored on the data storage devices is minimally updated only on the data storage devices affected by the operation. The metadata on unaffected storage devices is not changed such that processing time is improved. In another embodiment, the metadata may be differentiated into two types, global and local. Global metadata is maintained in a fully replicated way across all of the data storage devices. Local metadata containing information specific to a particular data storage device is maintained on that storage device but is not replicated on other storage devices. In this way, data storage space availability is improved. In still another embodiment, an in-memory data structure is constructed to maintain information derived from the stored local metadata. Full operation is possible despite failed or unavailable physical data storage devices.

Logical volume manager and method having enhanced update capability with

An apparatus and method is disclosed for scheduling a service (such as backup) in a complex computer installation given constraints of elapsed time and resource utilization. The apparatus form of the invention has two major components: a Modeler and a Scheduler. The Modeler calculates utilization of computer installation resources and elapsed time for the service for any subset of clients and/or networks using a model of the various client types, network types and their interconnections. The Scheduler invokes the Modeler with subsets of clients to find utilizations and elapsed times and adjusts the subsets to generate a schedule (if one exists) which is a list of subsets of clients which can be serviced concurrently without exceeding the utilization criterion or an elapsed time criterion. The Scheduler uses a heuristic involving client and network types to rapidly converge on the list of subsets of clients for the schedule to greatly improve over a trial and error approach.

Scheduling computerized backup services

This invention provides a one-pass storage process to manage storage space in a storage hierarchy system wherein whole objects or fragments of whole objects can be retrieved efficiently. Metadata to represent appropriate geometric characteristics of storage devices, units of transfer to minimize retrieval time, and buffers, are used to control the storage allocation. A plurality of objects from an object set are aggregated into at least one object grouping for storage where the object grouping is smaller than a minimum storage size. For each object grouping and each object not in an object grouping, a determination is made of the total number of blocks of storage needed and a minimum transfer size. Extents of blocks are identified in the storage device of a size greater than the minimum transfer size totalling the total number of blocks of storage needed.

System and method for allocating storage in a fragmented storage space

A system and method are provided for preserving spacial and temporal locality of sets of related objects when moving the sets within a storage hierarchy via a common server. The appropriate meta data is gathered to track the spacial and temporal locality of the sets of objects being moved within the storage hierarchy and the algorithm uses the meta data to preserve the spacial and temporal locality when moving the objects. A collection of logically clustered data objects is identified. The logical cluster is then moved down through the storage hierarchy together to be stored in less costly storage devices. The logical cluster of data objects is then retrievable more efficiently as a whole when requested.

System and method for managing a hierarchical storage system through

Growing community of inventors

San Jose, CA, United States of America

Luis Felipe Cabrera