Enhanced disk array

• US 20020156973A1
• Filed: 01/29/2002
• Published: 10/24/2002
• Est. Priority Date: 01/29/2001
• Status: Abandoned Application

• Current Assignee: Braodband Storage LLC, Snap Appliance, Inc. (Silicon Valley Technology Partners LLC)
• Original Assignee: Adaptec Incorporated (Steel Partners Holdings LP)
• Inventors: Schweitzer, James R., Bolstad, Gregory D., Staub, John R., Randall, Jay G., Priester, Wilbur George, Ulrich, Thomas R.
• Application Number:
  US10/060,863
• Publication Number:
  US 20020156973A1
• Time in Patent Office: Days
• US Class Current: 711/114
• 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

An enhanced disk array is described. The enhanced disk includes a plurality of disk drives for storing distributed parity groups. Each distributed parity group has a number of storage blocks including one or more data blocks and a parity block. Each of the storage blocks is stored on a separate disk drive such that no two storage blocks from a given parity group reside on the same disk drive. File system metadata describes a location of each storage block by specifying a disk identifier and a logical block identifier of a first logical block of each storage block. An allocation module allocates space for a new distributed parity group on two or more disk drives by allocating space for each storage block of the new distributed parity group from free space on each of the disk drives.

Claims

1. A computer storage system, comprising:

a plurality of disk drives for storing distributed parity groups, each distributed parity group comprising storage blocks, said storage blocks comprising one or more data blocks and a parity block, 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;

file system metadata to describe a location of each of said storage blocks by specifying a disk identifier and a logical block identifier of a first logical block of each storage block; and

an allocation module configured to allocate space for a new distributed parity group on two or more disk drives in said plurality of disk drives, said allocation module allocating space for each storage block of said new distributed parity group from free space on each of said two or more disk drives.

2. The computer storage system of claim 1, said allocation module further configured to recognize a new disk drive hot-swapped into said plurality of disk drives during file system operation and to use said new disk drive to store one or more storage blocks.

3. The computer storage system of claim 1, said allocation module further configured to recognize a new disk drive hot-swapped into said plurality of disk drives during file system operation and to use any free logical blocks on said new disk drive to store one or more storage blocks.

4. The computer storage system of claim 3, wherein said new disk drive is larger in capacity than any drive is said plurality of disk drives.

5. The computer storage system of claim 1, wherein a size of a first distributed parity group is larger than a size of a second distributed parity group within a first file.

6. The computer storage system of claim 1, wherein said new disk drive is provided to a Fibre Channel network.

7. The computer storage system of claim 1, wherein a file is organized as one or more distributed parity groups of varying size.

8. The computer storage system of claim 1, wherein an extent of a first distributed parity group of a file is larger than an extent of a second distributed parity group of said file.

9. The computer storage system of claim 1, further comprising a load-balancing module to move one or more distributed parity groups from disk to disk to improve load balancing of said plurality of disks.

10. The computer storage system of claim 1, further comprising a load-balancing module to move one or more distributed parity groups from disk to disk to improve capacity balancing of said plurality of disks.

11. The computer storage system of claim 1, further comprising a load-balancing module to move one or more distributed parity groups from disk to disk to improve load balancing of said plurality of disks when a new disk is added to said plurality of disks.

12. The computer storage system of claim 1, further comprising a load-balancing module to move one or more distributed parity groups from disk to disk to improve capacity balancing of said plurality of disks when a new disk is added to said plurality of disks.

14. The method of claim 13, wherein said updating comprises specifying a disk identifier and a logical block identifier.

15. The method of claim 13, wherein said new storage device comprises a new disk drive.

16. The method of claim 13, wherein said new disk drive is larger in capacity than other disk drives in said list of previously-available storage devices, and wherein said selected storage block can be stored on any unused logical block of said new disk drive.

13. A method for managing a storage array, comprising:

recognizing a new storage device;

adding said new storage device to a list of previously-available storage devices to produce a list of currently-available storage devices;

moving a selected storage block from a selected parity group to said new storage device;

updating file system metadata to reflect the new location of said selected storage device such that clients accessing a file containing said selected storage block can continue to access data in said selected storage block.