Data storage apparatus and method

• US 5,166,939 A
• Filed: 03/02/1990
• Issued: 11/24/1992
• Est. Priority Date: 03/02/1990
• Status: Expired due to Term

• Current Assignee: EMC Corporation (Dell Technologies Inc.)
• Original Assignee: Micron Technology, Inc.
• Inventors: Gajjar, Kumar, Glider, Joseph S., Jaffe, David H., Idleman, Thomas E., Powers, David T.
• Primary Examiner(s): Beausoliel, Robert W.
• Assistant Examiner(s): Lo, Allen M.
• Application Number:
  US07/488,749
• Time in Patent Office: 998 Days
• Field of Search: 371/40.1, 371/40.2, 371/40.4, 371/10.1, 371/10.2, 371/11.1, 364/200, 364/900
• US Class Current: 714/766
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 2211/103 Hybrid, i.e. RAID systems with parity comprising a mix of RAID types
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence

Abstract

A mass storage apparatus, made up of a plurality of physical storage devices, which is capable of providing both high bandwidth and high operation rate, as necessary, along with high reliability, is provided. The device set is divided into one or more redundancy groups. Each redundancy group is in turn divided into one or more data groups, each of which may span only a small number of the drives in the redundancy group, providing a high request rate, or which may span a large number of drives, providing high bandwidth.

Claims

1. A mass data storage apparatus for storing mass storage data for a plurality of application programs running on data processing devices, said mass storage apparatus comprising:

a set of physical mass storage devices, each physical mass storage device comprising a physical memory space divided into physical storage units; and

array controller means connected to said set for operatively interconnecting said set to form a composite memory space comprising the combined physical storage units of said physical mass storage devices, said array controller means including

means for configuring groups of said physical storage units within defined boundaries in said composite memory space into a plurality of redundancy groups to provide in each redundancy group a predetermined arrangement of physical data storage units for storing mass storage data received from said application programs and physical redundant information storage units for storing redundant information associated with said received mass storage data,

means for assigning sequential logical addresses to selected ones of the physical data storage units within each redundancy group to arrange said selected units in a logically contiguous data group having a configuration independent of said redundancy group in which said data group is formed,

means for correlating the sequential logical addresses of each data group to logical addresses in one of a plurality of logical mass storage units addressable by said application programs,

means responsive to I/O service requests from said application programs addressing logical address spans in said logical mass storage units for mapping said spans to sequences of logical addresses within said data groups to which said spans have been correlated by said correlating means, and for mapping said sequences to physical data storage units to which said sequences have been assigned by said assigning means, and

means responsive to receipt of mass storage data from said application programs for storing said received mass storage data in physical data storage units identified by said mapping means and for storing redundant information associated with said received mass storage data in physical redundant information storage units related to said identified physical data storage units by said redundancy group configuring means, whereby said composite memory space is organized at a first logical level as a plurality of redundancy groups, each of said redundancy groups including at a second logical level at least one independently configurable data group, each data group capable of operating as a separate logical mass data storage device.

2. The mass data storage apparatus of claim 1, wherein each redundancy group comprises a plurality of data groups.

3. The mass data storage apparatus of claim 2, wherein a data group can be characterized by a data group width to achieve a desired bandwidth or request rate.

4. The mass data storage apparatus of claim 3, wherein at least two data groups have different widths.

5. The mass data storage apparatus of claim 2, wherein at least two data groups have different lengths.

6. The mass data storage apparatus of claim 2, wherein at least two data groups have different bases.

7. The mass data storage apparatus of claim 1 further comprising a third logical level, wherein at least one data group from each of at least two of the plurality of redundancy groups are combined to form a single logical mass data storage device.

8. The mass data storage apparatus of claim 1, wherein for at least one of the plurality of redundancy groups redundancy is provided by check data comprising code words, the code words being stored in at least one check drive included in at least one redundancy group.

9. The mass data storage apparatus of claim 8, wherein each of the at least one check drive is a physical mass storage device.

10. The mass data storage apparatus of claim 8, wherein each of the at least one check drive is a logical mass storage device comprising portions of a plurality of physical mass storage devices.

11. The mass data storage apparatus of claim 10, wherein code words are distributed across the redundancy group.

12. The mass data storage apparatus of claim 1, wherein for at least one of the plurality of redundancy groups redundancy is provided by mirroring.

13. The mass data storage apparatus of claim 12, wherein redundancy data is stored in at least one redundant drive included in the redundancy group.

14. The mass data storage apparatus of claim 13, wherein each of the at least one redundant drive is a physical mass storage device.

15. The mass data storage apparatus of claim 13, wherein each of the at least one redundant drive is a logical mass storage device comprising portions of a plurality of physical mass storage devices.

16. The mass data storage apparatus of claim 15, wherein redundant data is distributed across the redundancy group.

17. The mass data storage apparatus of claim 1, wherein a redundancy group can be characterized by a redundancy group width to achieve a desired data capacity for the redundancy group.

18. The mass data storage apparatus of claim 17, wherein at least two redundancy groups have different group widths.

19. The mass data storage apparatus of claim 1, wherein each data block comprises a sector of data memory on a disk drive.

20. The mass data storage apparatus of claim 1, wherein at least one of said data groups comprises physical data storage units from a plurality of physical mass storage devices.

21. The mass data storage apparatus of claim 1, wherein each of said data groups comprises physical data storage units from a plurality of physical mass storage devices.

22. A mass data storage apparatus for storing mass storage data for a plurality of application programs running on data processing devices, said mass storage apparatus comprising:

a set of physical mass storage devices, each physical mass storage device comprising a physical memory space divided into physical storage units; and

array controller means connected to said set for operatively interconnecting said set to form a composite memory space comprising the combined physical storage units of said physical mass storage devices, said array controller means including

means for configuring a group of said physical storage units within a defined boundary in said composite memory space into a redundancy group to provide within the redundancy group a predetermined arrangement of physical data storage units for storing mass storage data received from said application programs and physical redundant information storage units for storing redundant information associated with said received mass storage data,

means for assigning sequential logical addresses in groups to selected ones of the physical data storage units within said redundancy group to arrange said units in a plurality of data groups having configurations independent of said redundancy group,

means for correlating the sequential logical addresses of said data groups to logical addresses in respective ones of a plurality of logical mass storage units addressable by said application programs,

means responsive to I/O service requests from said application programs addressing spans of logical addresses in said logical mass storage units for mapping said spans to sequences of logical addresses within said data groups with which said spans have been correlated by said correlating means, and for mapping said sequences to physical data storage units to which said sequences have been assigned by said assigning means, and

means responsive to receipt of mass storage data from said application programs for storing said received mass storage data in physical data storage units identified by said mapping means and for storing redundant information associated with said received mass storage data in physical redundant information storage units related to said identified physical data storage units by said redundancy group configuring means, whereby said composite memory space is organized at a first logical level as at least one redundancy group, each of said at least one redundancy device group including at a second logical level a plurality of independently configurable data groups, each data group capable of operating as a separate logical mass data storage device.

23. The mass data storage apparatus of claim 22, wherein the set of physical mass storage devices comprises at the first logical level a plurality of redundancy groups.

24. The mass data storage apparatus of claim 23, further comprising a third logical level, wherein at least one data group from each of at least two of the plurality of redundancy groups are combined to form a single logical mass data storage device.

25. The mass data storage apparatus of claim 24, wherein at least two data groups have different widths.

26. The mass data storage apparatus of claim 23, wherein for at least one of the plurality of redundancy groups redundancy is provided by check data comprising code words, the code words being stored in at least one check drive included in the redundancy group.

27. The mass data storage apparatus of claim 26, wherein each of the at least one check drive is a physical mass storage device.

28. The mass data storage apparatus of claim 26, wherein each of the at least one check drive is a logical mass storage device comprising portions of a plurality of physical mass storage devices.

29. The mass data storage apparatus of claim 28, wherein code words are distributed across the redundancy group.

30. The mass data storage apparatus of claim 23, wherein for at least one of the plurality of redundancy groups redundancy is provided by mirroring.

31. The mass data storage apparatus of claim 30, wherein redundancy data is stored in at least one redundant drive included in the redundancy group.

32. The mass data storage apparatus of claim 31, wherein each of the at least one redundant drive is a physical mass storage device.

33. The mass data storage apparatus of claim 31, wherein each of the at least one redundant drive is a logical mass storage device comprising portions of a plurality of physical mass storage devices.

34. The mass data storage apparatus of claim 33, wherein redundant data is distributed across the redundancy group.

35. The mass data storage apparatus of claim 23, wherein a data group can be characterized by a data group width to achieve a desired bandwidth or request rate.

36. The mass data storage apparatus of claim 23, wherein at least two data groups have different lengths.

37. The mass data storage apparatus of claim 23, wherein at least two data groups have different bases.

38. The mass data storage apparatus of claim 22, wherein a redundancy group can be characterized by a redundancy group width to achieve a desired data capacity for the redundancy group.

39. The mass data storage apparatus of claim 22, wherein at least two redundancy groups have different group widths.

40. The mass data storage apparatus of claim 22, wherein each data block comprises a sector of data memory on a disk drive.

41. The mass data storage apparatus of claim 22, wherein at least one of said data groups comprises physical data storage units from a plurality of physical mass storage devices.

42. The mass data storage apparatus of claim 22, wherein each of said data groups comprises physical data storage units form a plurality of physical mass storage devices.