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, 2015
Filed:
Mar. 29, 2013
Emc Corporation, Hopkinton, MA (US);
Edward L. Thigpen, Raleigh, NC (US);
Michael E. Bappe, Loveland, CO (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
A data migration operation uses an error flag to protect against data corruption. During write cloning states, the error flag is set and only allowed state transitions are performed, including a non-error transition to a committed state when no device fault is recorded for a target storage device and an error transition to a setup state when a device fault is recorded for the target storage device. In a clean system shutdown, a shutdown procedure records a detected target storage device fault and clears the error flag; the recorded device fault later forces the error transition of the migration operation. During the system startup, if the error flag is set then a target storage device fault is recorded to likewise later force the error transition of the migration operation, on the assumption that a detected fault may exist but be unrecorded because the shutdown procedure did not complete during shutdown.