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:
Jun. 03, 2014
Filed:
Sep. 29, 2006
Marc Desouter, Wayne, NJ (US);
Pranit Sethi, Piscataway, NJ (US);
Marc DeSouter, Wayne, NJ (US);
Pranit Sethi, Piscataway, NJ (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
A networked data storage system includes a primary volume and a pointer-based virtual secondary volume. The secondary volume has B-tree checkpoints of the state of a primary filesystem of the primary volume. Intermediate syncpoints are declared between checkpoint checkpoints. The syncpoints are logical locations on the secondary volume where the B-tree is known to be in a consistent state. The frequency of syncpoints may be set by an administrator in units of blocks, i.e., a syncpoint to be taken every n blocks. Before performing a B-tree split, entire images of the leaves and parent node involved in the split are written to an intent log in a relatively fast transaction that may comprise a single I/O operation to contiguous memory. Movement of data between leaf nodes and changes to the parent nodes as a result of the split operation proceed asynchronously. In the event of a reboot before the split operation is complete, the intent log is used to complete the split transaction from the most recent syncpoint. When a new syncpoint is declared, the intent log and dirty leaves are flushed.