(12) United States Patent ao) Patent No.: Us 7,337,289 B2
Pillai et al. (45) Date of Patent: Feb. 26,2008
(54) METHOD AND APPARATUS FOR
COMPUTING FILE STORAGE ELEMENTS
FOR BACKUP AND RESTORE
(75) Inventors: Ananthan Pillai, East Norwood, MA
(US); Madhav Mutalik, Southborough,
MA (US); Cara Garber, Franklin, MA
(US); Ajay Shekhar, Medway, MA
(73) Assignee: EMC Corporation, Hopkinton, MA
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 288 days.
(21) Appl. No.: 11/143,272
(22) Filed: Jun. 2, 2005
(65) Prior Publication Data
US 2005/0235122 Al Oct. 20, 2005
Related U.S. Application Data
(63) Continuation of application No. 09/822,709, filed on Mar. 30, 2001, now Pat. No. 6,912,630.
(58) Field of Classification Search None
See application file for complete search history.
A method and apparatus for method for transferring files between a primary storage system and a backup and restore system is described. The system generates collapsed extents which are used to specify data to be backed up to a backup and restore system. The backup and restore system backs up data based on the collapsed extents but records all extents included in the collapsed extents to enable the system to facilitate restoration of the data at a later point in time.
15 Claims, 8 Drawing Sheets