David J Nagle

US Patent:

7681072, Mar 16, 2010

Filed:

Aug 7, 2007

Appl. No.:

11/835147

Inventors:

Garth A. Gibson - Pittsburgh PA, US
Marc Jonathan Unangst - Pittsburgh PA, US
David F. Nagle - New York NY, US

Assignee:

Panasas, Inc. - Pittsburgh PA

International Classification:

G06F 11/00

US Classification:

714 6

Abstract:

A system includes storage devices where a RAID-X format is implemented at a file level. In response to a failure, a map is retrieved. The map includes a list of devices where components of at least one file reside. The map is used to determine whether a number of lost or damaged components associated with the file exceed a maximum limit beyond which reconstruction of a file stored using the file level implementation of the RAID-X format is not possible. If the maximum limit has not been exceeded, the file is reconstructed. The system continues to service data storage and access requests, with reconstruction being performed as a background operation, after a number of device failures has occurred which would have exceeded the maximum limit of device failures for reconstruction had the file been stored using a volume level implementation of the RAID-X format.