Instant copy of data through pointers interchanging

US7640410B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Ofir Zohar · Gdera, IL
• Haim Helman · Ramat Gan, IL
• Dror Cohen · Even Yehuda, IL
• Shemer Schwartz · Herzliya, IL
• Yaron Revah · Nes Ziona, IL
• Efri Zeidner · Kfar Sava, IL

Key dates

• Filing date: Jul 21, 2006
• Grant date: Dec 29, 2009
• Expiry date: May 5, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F12/0866
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A system and method are described to improve the efficiency of copy-on-write operations in a storage system. A partition mapping table is maintained in a cache memory, where the partition mapping table is used to translate logical partitions into physical partitions. A request is received to write one or more blocks BB to a partition PSS, and, upon receiving the request, the pointers in the partition mapping table are interchanged such that data associated with PSS is now associated with a second partition PTT. Next, block(s) BB is written to PSS and an indication is made on the PDSS descriptor that all other data blocks in the partition PSS are invalid.