Efficient and reliable virtual volume mapping

Patent 7191304 Issued on March 13, 2007. Estimated Expiration Date:

September 4, 2023. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Method for maintaining consistent states of a file system and for creating user-accessible read-only copies of a file system
Patent #: 5819292
Issued on: 10/06/1998
Inventor: Hitz, et al.

Write anywhere file-system layout
Patent #: 5963962
Issued on: 10/05/1999
Inventor: Hitz, et al.

System and method for real-time data backup using snapshot copying with selective compaction of backup data
Patent #: 6061770
Issued on: 05/09/2000
Inventor: Franklin

Write anywhere file-system layout
Patent #: 6289356
Issued on: 09/11/2001
Inventor: Hitz, et al.

System and method for disk control with snapshot feature including read-write snapshot half
Patent #: 6341341
Issued on: 01/22/2002
Inventor: Grummon, et al.

File system image transfer Patent #: 6604118
Issued on: 08/05/2003
Inventor: Kleiman, et al.

Inventors

Assignee

3PARdata, Inc.

Application

No. 10655963 filed on 09/04/2003

US Classes:

711/202, Address mapping (e.g., conversion, translation)711/162, Backup707/204Archiving or backup

Examiners

Primary: Lane, Jack A.

Attorney, Agent or Firm

International Class

G06F 12/16

Abstract

A snapshot tree structure includes a base volume storing a current user data, a first snapshot descending from the base volume, and a second snapshot descending from the first snapshot, wherein the second snapshot was created prior to the first snapshot. The first snapshot includes a first table corresponding to first portions of block addresses, a second table corresponding to second portions of the block addresses, and a third table to third portions of the block addresses. The first table includes an entry with a pointer to the second table. The second table includes an entry with a pointer to the third table. The third table includes an entry with a pointer to a data of the base volume before the data is modified in the base volume.

Other References

Suresh B. Siddha et al., “A Persistent Snaopshot Device Driver for Linux”, published Sep. 13, 2001, downloaded from http://www.linuxshowcase.org/full_—papers/siddha/siddha_—html/index.html on May 15, 2002.
Dave Hitz et al., “File System Design for an NFS File Server Appliance”, paper downloaded from http://www.netapp.com/tech_—library/3002.html on Sep. 30, 2002, 13 pages.
“Snapshot Feature”, LSI Logic Storage Systems, SANtricity brochure, 2 pages.
“The Enterprise Challenge Served by Snapshot”, Whitepaper, LSI Logic Storage Systems, pp. 1-8.
Suresh B. Siddha et al., “A Persistent Snapshot Device Driver for Linux”, Proceedings of the 5th Annunal Linux Showcase & Conference, Oakland, CA, USA, Nov. 5-10, 2001.