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:
May. 25, 1999
Filed:
Jul. 17, 1997
Hideaki Hirayama, Tokyo, JP;
Toshio Shirakihara, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A computer system which can achieve rollback operation when a fault occurs in the system without waiting for side-tracking of pre-update data during updating of a file. When a file write request has been made, 'file writing information' pertaining to the file write is saved in a pending queue and only a primary file is immediately updated. After a checkpoint has been acquired, the 'file writing information' saved in the pending queue is shifted to a confirmed queue, and is then written to a back-up file. When performing recovery, all pre-update data which corresponds to the data which has been updated since the last checkpoint acquired is read from the back-up file, based on the 'file writing information' saved in the pending queue. The primary file is then restored to its state at the checkpoint time by using the pre-update data which has been read from the backup file.