Patent ID: 6092071
Filing Date: 2000-07-18
Classification: G06F,G11B,H03M,Y10S

Abstract:
Method for managing data objects in a system including a central processor, a main storage, a remote storage, and a compression input/output processor, comprising the steps of:responsive to a system managed aging algorithm, compressing an uncompressed data object according to the steps of:reading said uncompressed data object from remote storage into main storage;loading into said main storage a compression control block, said compression control block including a compression start I/O operation command, a data out descriptor giving the address in main storage of said uncompressed data object, and a data in descriptor giving the address in main storage into which a resulting compressed data object is to be stored;responsive to said compression start I/O operation command, writing said compression control block to said compression input/output processor;operating said compression input/output processor to (a) load said uncompressed data object to said compression input/output processor from the main storage location addressed by said data out descriptor, (b) compress said uncompressed data object, and (c) load the resulting compressed data object to the main storage location addressed by said data in descriptor; andwriting said compressed data object to said remote storage from said main storage; andresponsive to an application request for access to a compressed data object, decompressing said compressed data object according to the steps of:reading said compressed data object from remote storage into main storage;loading into said main storage a decompression control block, said decompression control block including a decompression start I/O operation command, a data out descriptor giving the address in main storage of said compressed data object, and a data in descriptor giving the address in main storage into which a resulting decompressed data object is to be stored;responsive to said decompression start I/O operation command, writing said decompression control block to said compression input/output processor;operating said compression input/output processor to (a) load said compressed data object to said compression input/output processor from the main storage location addressed by said data out descriptor, (b) decompress said compressed data object, and (c) load the resulting decompressed data object to the main storage location addressed by said data in descriptor;writing said decompressed data object to said remote storage from said main storage; andgranting said application request.