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:
Dec. 24, 2002
Filed:
Sep. 23, 1999
Dinesh Venkatesh, North Andover, MA (US);
Wayne W. Duso, Shrewsbury, MA (US);
John Forecast, Newton, MA (US);
Uday Gupta, Westford, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
To reorganize a striped file system, data blocks are sequentially moved from storage locations in original data storage to storage locations in an array including the original data storage and additional data storage. If the new striping has the same precedence order as the original striping, then temporary storage is not needed for the block movement. Otherwise, stripes of the data blocks are sequentially moved to a stripe of temporary storage locations, and moved from the stripe of the temporary locations to storage locations in the array. Once a pivot point is reached, however, there is no need to use the temporary storage. Moreover, there is an increasing separation between the read and write pointers. Once this separation exceeds the stripe length, the file system metadata can be synchronized at decreasing intervals and still permit concurrent read access. The number of block transfers between the synchronization points can increase exponentially, and the synchronization points can be aligned with extent boundaries.