Discrete mapping of parity blocks

• US 6,775,792 B2
• Filed: 01/29/2002
• Issued: 08/10/2004
• Est. Priority Date: 01/29/2001
• Status: Expired due to Term

• Current Assignee: Braodband Storage LLC, Overland Storage Incorporated (Silicon Valley Technology Partners LLC)
• Original Assignee: Snap Appliance, Inc. (Silicon Valley Technology Partners LLC)
• Inventors: Schweitzer, James R., Bolstad, Gregory D., Staub, John R., Randall, Jay G., Ulrich, Thomas R., Priester, George W.
• Primary Examiner(s): PEIKARI, BEHZAD
• Application Number:
  US10/060,921
• Publication Number:
  US 20020166026A1
• Time in Patent Office: 924 Days
• Field of Search: 714/6, 714/8, 714/42, 711/112, 711/114
• US Class Current: 714/6.12
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 9/5083 Techniques for rebalancing the load in a distributed system

Abstract

A system and method for discrete mapping of parity blocks in a computer storage system that includes a plurality of disk drives for storing parity groups. Each parity group includes storage blocks. The storage blocks include one or more data blocks and a parity block that is associated with the one or more data blocks. Each of the storage blocks is stored on a separate disk drive such that no two storage blocks from a given parity set reside on the same disk drive. File system metadata includes information to describe the data blocks in one or more parity groups.

Claims

1. A computer storage system comprising:

a plurality of disk drives for storing parity groups, each parity group comprising storage blocks, said storage blocks comprising one or more data blocks and a parity block associated with said one or more data blocks, each of said storage blocks stored on a separate disk drive such that no two storage blocks from a given parity group reside on the same disk drive, wherein file system metadata comprises information to describe the data blocks in one or more parity groups, and wherein said file system metadata further comprises at least one Gnid-string that comprises a collection of gnids, wherein each of said gnids comprises information for locating a specified gnode.

2. The computer storage system of claim 1, wherein said information for locating a specified gnode comprises a pointer to said specified gnode.

3. The computer storage system of claim 1, wherein said specified gnode comprises file attributes for a file corresponding to said gnode.

4. The computer storage system of claim 3, wherein said file attributes include at least one of a file id, a file access time, a file creation time, and a file modification time.

5. The computer storage system of claim 1, wherein said specified gnode comprises information for locating a first gee of a plurality of gees corresponding to said gnode.

6. The computer storage system of claim 5, wherein said plurality of gees comprises gnode gees and data gees.

7. The computer storage system of claim 6, wherein each of said gnode gees comprises information to specify an extent.

8. The computer storage system of claim 6, wherein each of said data gees comprises information to specify a first logical disk block and information to specify which of said disk drives contains said first logical block.

9. The computer storage system of claim 6, wherein said plurality of gees further comprises parity gees.

10. The computer storage system of claim 9, wherein each of said parity gees comprises information regarding location of parity data for one or more preceding data gees in said plurality of gees.

11. The computer storage system of claim 5, wherein a parity group comprises a first set of one or more data gees and an associated parity gee.

12. The computer storage system of claim 11, wherein each data gee identifies a block of data and said parity gee identifies a parity block.