Abstract: Method, apparatus and program product are provided for rebuilding faulty metadata in a storage controller coupled to a host device. Faulty metadata may include metadata which no longer matches the associated customer data tracks stored on a DASD or other storage device. When an error in metadata is describing a first customer track is detected, a range of other customer tracks in which the error is also likely to have occurred is identified. The metadata tracks associated with the first customer track and the other customer tracks are selected to be invalidated. A command is received through a host interface, and the specified metadata tracks are invalidated while the controller remains on-line with the host and continues to process other host I/O operations. Subsequently, the invalidated metadata tracks are rebuilt. The disclosed method, apparatus and program product invalidate the faulty metadata with reduced impact on normal host/controller I/O operations.

Abstract: Method, apparatus and program product are provided for the invalidation of faulty metadata in a storage controller coupled to a host device. Faulty metadata may include metadata which no longer matches the associated customer data tracks stored on a DASD or other storage device. When faulty metadata is detected, metadata tracks are selected to be invalidated. A command is received through a host interface, without the controller being taken off-line from the host, and the specified metadata tracks are invalidated. Subsequently, the invalidated metadata tracks are rebuilt. The disclosed method, apparatus and program product invalidate the faulty metadata with reduced impact on normal host/controller I/O operations.

Abstract: A storage system improves error debugging by directing distributed system components associated with an error condition to temporarily suspend data processing for collecting failure information. The collected failure information is correlated for later analysis according to an issued diagnostic state save channel command word (CCW) that is triggered by the detection of said error condition. The storage system includes a host processor running applications generating record updates. A data mover in the host processor issues the diagnostic state save CCW upon receiving an error code from one of the system components. The failure information includes software, hardware and microcode control structures of the distributed system components.

Abstract: A remote data shadowing system provides storage based, real time disaster recovery capability. Record updates at a primary site cause write I/O operations in a storage subsystem therein. The write I/O operations are time stamped and the time, sequence, and physical locations of the record updates are collected in a primary data mover. The primary data mover groups sets of the record updates and associated control information based upon a predetermined time interval, the primary data mover appending a prefix header to the record updates thereby forming self describing record sets. The self describing record sets are transmitted to a remote secondary site wherein consistency groups are formed such that the record updates are ordered so that the record updates can be shadowed in an order consistent with the order the record updates cause write I/O operations at the primary site.

Abstract: A method in a data processing system for generating a backup copy of designated datasets during concurrent execution of an application. Upon receiving a request for a backup copy, execution of an application is suspended. A dataset logical-to-physical storage system address concordance for the designated datasets is formed, and execution of the application is resumed thereafter. A resource manager is established to manage all input and output functions between storage subsystems, storage subsystem memory associated with each of the storage subsystems, and a temporary host memory during formation of the backup copy. Formation of the backup copy is accomplished on a scheduled or opportunistic basis by copying the designated datasets from the storage subsystems and then updating the address concordance in response to the copying.

Abstract: An updatable and expandable directory structure and resultant access procedures emulating a write-once or indelible record medium to a rewriteable record medium as to accessing characteristics. The directory is indexed; one directory header for a first set of files indexes another set of files. Sector clusters or data extends are managed such that random recording from any file proceeds independently of write-once characteristics. The directory is stored on the medium as data is recorded. Each directory entry contains an archival history of recording of a related data file in the medium. Both logical and physical addressing is employable.

Abstract: An updatable and expandable directory structure and resultant access procedures emulating a write-once or indelible record medium to a rewriteable record medium as to accessing characteristics. The directory is indexed; one directory header for a first set of files indexes another set of files. Sector clusters or data extents are managed such that random recording from any file proceeds independently of write-once characteristics. The directory is stored on the medium as data is recorded. Each directory entry contains an archival history of recording of a related data file in the medium. Both logical and physical addressing is employable.