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:
Mar. 10, 1998
Filed:
Jul. 31, 1996
Robert W Fish, W. Chicago, IL (US);
Lawrence J Schroeder, Wheaton, IL (US);
NCR Corporation, Dayton, OH (US);
Abstract
A method for identifying and repairing file system damage following the failure of a processing node within a clustered UNIX file system including a plurality of processing nodes, an interconnection network connecting the processing nodes, and a data storage device connected via a shared interconnect with each one of the plurality of processing nodes. The method includes the step of maintaining a journal for each processing node, each journal containing a bit map identifying inodes to which its associated processing node has acquired and retains an exclusive right. Each bit map journal is updated whenever its associated processing node acquires an exclusive right to an inode. Following a failure of a processing node, a non-failed processing node is designated to audit the inodes associated with the failed node. Auditing is accomplished by reading the bit map journal associated with the failed processing node and obtaining the exclusive right to every inode found within the journal. The inodes within the bit map journal, referred to as suspect inodes, are then compared with a global bit map which identifies each and every unit of space within the file system that is assignable. A suspect node is identified as having a transient state when the unit of space assigned to the suspect inode is also found to be assignable. The assignment of a unit of file system space to any suspect inode identified as having a transient state is thereafter discarded.