The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 07, 2003
Filed:
Feb. 20, 2001
Hitachi, Ltd., Tokyo, JP;
Abstract
A plurality of processors of a disk controller are divided into a plurality of clusters. In normal operation, data is transferred between a host computer and a disk drive in a cluster non-restricted processing mode in which a job can be distributedly processed among processors belonging to any clusters without regard to cluster. In response to a program version upgrading command from an operator, the cluster mode is shifted from the cluster non-restricted processing mode to a cluster restricted processing mode in which the cluster to which processors which are permitted to distributedly process one job belong is restricted. When the shifting to the cluster restricted processing mode is completed, one cluster is selected as a cluster to be maintained and versions of the programs to be executed by the processors belonging to the cluster to be maintained are upgraded. When the versions of the programs of all processors of the cluster to be maintained have been upgraded, the acceptance of a new job by the processors belonging to the cluster to be maintained is resumed and the execution of the new programs is started. The selection of the cluster, the version upgrading of the programs and the start of the execution of the new programs are repeated sequentially for all clusters. When the version upgrading of the programs of all processors is completed, the cluster mode is returned from the cluster restricted processing mode to the cluster non-restricted process mode.