Browse Prior Art Database

Shared Resource Management

IP.com Disclosure Number: IPCOM000052792D
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Kamionka, HE: AUTHOR

Abstract

Shared resources have availability and operability dependent on a plurality of conditions, such as free space in a storage device. These conditions must be known to all processors in a multiprocessing environment. Efficiency of the installation is enhanced by having one of the processors, and only one of the processors, scan the shared resources for developing status information concerning selective conditions, such as free space. The one processor then broadcasts the accumulated information to all of the other processors. This eliminates the need for all of the processors to sense the shared resources for developing condition information. Provisions are made for recovery from the one processor failure, such that the multiprocessing installation operability is not dependent upon a single processor.

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Shared Resource Management

Shared resources have availability and operability dependent on a plurality of conditions, such as free space in a storage device. These conditions must be known to all processors in a multiprocessing environment. Efficiency of the installation is enhanced by having one of the processors, and only one of the processors, scan the shared resources for developing status information concerning selective conditions, such as free space. The one processor then broadcasts the accumulated information to all of the other processors. This eliminates the need for all of the processors to sense the shared resources for developing condition information. Provisions are made for recovery from the one processor failure, such that the multiprocessing installation operability is not dependent upon a single processor. The term host is used for processor.

A plurality of hosts and a primary host (PH) share direct-access storage devices (DASDs) as a common storage set of elements. Each DASD has a volume table of contents (VTOC) which indicates the status of the storage device. Such VTOCs will include the number of free bytes, the extent of the various free bytes, and a fragmentation index, among other control information. In order to balance the usage of the DASD by the various hosts, free-space checks are made periodically so that the using host can apply this information to their space allocation routines. An efficient space check routine includes the PH at 1, scanning all VTOCs and accumulating free space and other operational information, as may be desired. This can take an extended period of time. A...