Enhanced DASD with smaller supplementary DASD

• US 6,594,724 B1
• Filed: 03/30/2000
• Issued: 07/15/2003
• Est. Priority Date: 03/30/2000
• Status: Expired due to Fees

• Current Assignee: HGST Netherlands B.V. (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: Smith, Gordon James
• Primary Examiner(s): Thai, Tuan V.
• Application Number:
  US09/539,155
• Time in Patent Office: 1,202 Days
• Field of Search: 711/100, 711/3, 711/111, 711/112, 711/113, 711/114, 711/115, 711/154
• US Class Current: 711/112
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: G06F 11/0787 Storage of error reports, e.g. persistent data storage, storage using memory protection
• CPC Class Codes: G06F 11/2087 with a common controller
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G11B 2220/2516 Hard disks
• CPC Class Codes: G11B 2220/41 Flat as opposed to hierarchical combination, e.g. library of tapes or discs, CD changer, or groups of record carriers that together store one title
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06

Abstract

A digital access storage device comprises a first disk drive, at second disk drive smaller than the first disk drive, the drives are physically mounted on a common chassis, and an electronic control system interconnecting said first and second disk drives. In a preferred embodiment, the storage device has a system interface and the electronic control system is structured to transfer data between the device interface, the first disk drive, and the second disk drive using the first drive'"'"'s internal data paths and processor speeds, electronic control system comprises a shared system control processor is structured to provide overall control of the first and second disk drives.

Claims

1. A digital access storage device comprising:

a first disk drive;

at least one second disk drive, wherein said second disk drive being smaller than said first disk drive, said second drive having a data transfer rate less than or equal to the data transfer rate of said first drive; and

an electronic control system interconnecting said first and second disk drives;

wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks; and

throughput data of the device comprises stripes of data from both the first and second disk drives;

wherein the electronic control system comprises a shared system control processor structured to adjust the length of the stripes of data from the first and second disk drives so the throughput data flow of the device is constant.

2. A digital access storage device according to claim 1 wherein the storage device has a system interface and the electronic control system is structured to transfer data between the device interface, the first disk drive, and the second disk drive using the first drive'"'"'s internal data paths and processor speeds.

3. A digital access storage device according to claim 2 wherein the electronic control system comprises a shared system control processor structured to provide overall control of the first and second disk drives.

4. A digital access storage device according to claim 3 wherein said drives are physically mounted on a common chassis.

5. A digital access storage device according to claim 3 wherein the electronic control system comprises an independent controller for the first disk drive, an independent controller for the second disk drive, and a shared data memory buffer both the first and second disk drives.

6. A digital access storage device according to claim 5 wherein the shared system control processor is structured to control the flow of data between the system interface, the first disk drive, and the second disk drive.

7. A digital access storage device according to claim 1 wherein said drives are physically mounted on a common chassis.

8. A digital access storage device according to claim 7 wherein the electronic control system is structured so that the electronic functionality of the second disk drive is embedded in the electronic functionality of the first disk drive.

9. A digital access storage device according to claim 8 wherein the second disk drive is an embedded memory component of the first disk drive.

10. A digital access storage device according to claim 7 wherein the second disk drive has a capacity of at least 340 Megabytes.

11. A digital access storage device according to claim 1 wherein the second disk drive comprises a microdrive and wherein the electronic control system comprises a compact flash microdrive controller and a compact flash microdrive interface for controlling the second disk drive.

12. A digital access storage device according to claim 1 wherein the first and second disk drives have non-volatile redundant data.

13. A digital access storage device according to claim 1 comprising a non-volatile memory cache on the second disk drive, wherein the electronic control system is structured to control the reading and writing of data from the first disk drive to the non-volatile memory cache on the second disk drive.

14. A digital access storage device according to claim 12 wherein the non-volatile memory cache is comprises a portion of the disk data section of the second disk drive.

15. A digital access storage device according to claim 13 wherein the second disk drive functions as a second-level read and write cache in addition to the first disk drive'"'"'s regular cache.

16. A digital access storage device according to claim 13 wherein electronic control system is structured to provide read and write data from the non-volatile memory cache on the second drive prior to spin-up of the first disk drive.

17. A digital access storage device according to claim 1 comprising a non-volatile error log on the first disk drive and on the second disk drive.

18. A digital access storage device according to claim 17 wherein the non-volatile error log on the second disk drive is capable of recording a detailed record of errors.

19. A digital access storage device according to claim 17 wherein the non-volatile error log on the second disk drive comprises a copy of the error log for the first disk drive.

20. A digital access storage device according to claim 17 wherein the non-volatile error log on the first disk drive comprises a copy of the error log for the second disk drive.

21. A digital access storage device according to claim 1 wherein the electronic control system is structured to provide parallel access to redundant data on the first disk drive and on the second disk drive.

22. A digital access storage device according to claim 21 comprising a video or/and audio stream playback buffer on the second disk drive.

23. A digital access storage device according to claim 22, wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks.

24. A digital access storage device according to claim 1 wherein said stripes are asymmetrical in length.

25. A digital access storage device according to claim 1 wherein the length of a stripe of data from the first disk drive is 5-10 times larger than that of a stripe from the second disk drive.

26. A digital access storage system comprising:

a first disk drive having a pre-determined size;

at least one second disk drive, said second disk drive being smaller than the first disk drive, said second drive having a data transfer rate less than or equal to the data transfer rate of said first drive;

an electronic control system interconnecting said first and second disk drive; and

wherein said drives are physically mounted on a common chassis;

wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks; and

throughput data of the device comprises stripes of data from both the first and second disk drives;

wherein the electronic control system comprises a shared system control processor structured to adjust the length of the stripes of data from the first and second disk drives so the throughput data flow of the device is constant.

27. A digital access storage device according to claim 26 wherein said common chassis has a standard form factor.

28. A digital access storage device according to claim 26 wherein the chassis (device) fits into the standard form factor disk drive slot.

29. A digital access storage device according to claim 28 wherein the chassis fits into a standard form 3.5″

disk drive slot.

30. A digital access storage device according to claim 26 wherein the first disk drive substantially conforms to a first standard form factor, and the second disk drive substantially conforms to a second smaller standard form factor.

31. A digital access storage device according to claim 30 wherein the first disk drive is a traditional 3.5-inch form factor.

32. A digital access storage device according to claim 30 wherein the second disk drive is a 4.28×

3.36×

0.5-cm form factor.

33. A digital access storage device according to claim 26 comprising a receptacle wherein the second disk drive may be removably plugged.

34. A digital access storage device according to claim 33 wherein the first disk drive comprises an electronic card and wherein said receptacle is located on the electronic card.

35. A digital access storage device according to claim 33 comprising a casting of the first disk drive upon which the second disk drive is mounted.

36. A digital access storage device according to claim 26 comprising a second disk assembly unit comprising the second disk drive and an independent controller for the second disk drive.

37. A digital access storage device according to claim 26 wherein the electronic control system is structured so that the electronic functionality of the second disk drive is physically embedded into the electronic functionality of the first disk drive.

38. A digital access storage device according to claim 26 further comprising a single power supply cable and a single data cable.

39. A method of manufacturing a digital access storage device comprising steps of:

providing a first disk drive;

providing at least one second disk drive, said second disk drive being smaller than the first disk drive, said second drive having a data transfer rate less than or equal to the data transfer rate of said first drive; and

providing an electronic control system interconnecting said first disk drive and said second disk drive;

wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks; and

throughput data of the device comprises stripes of data from both the first and second disk drives

wherein the electronic control system comprises a shared system control processor structured to adjust the length of the stripes of data from the first and second disk drives so the throughput data flow of the device is constant.

40. A method of manufacturing a digital access storage device according to claim 39, comprising the steps of providing a system interface and structuring the electronic control system to transfer data between the interface, the first disk drive, and the second disk drive employing the first drive'"'"'s internal data paths and processor speeds.

41. A method of manufacturing a digital access storage device according to claim 39 wherein the electronic control system comprises a shared system control processor structured to provide overall control of the first and second disk drives.

42. A method of manufacturing a digital access storage device according to claim 39 comprising the step of physically mounting said drives on a common chassis.

43. A method of manufacturing a digital access storage device according to claim 39 wherein the electronic control system is provided which comprises an independent controller for the first disk drive, an independent controller for the second disk drive, and a shared data memory buffer both the first and second disk drives.

44. A method of manufacturing a digital access storage device according to claim 43 wherein the shared system control processor is structured to control the flow of data between the system interface, the first disk drive, and the second disk drive.

45. A method of manufacturing a digital access storage device according to claim 43 comprising the step of physically mounting said drives on a common chassis.

46. A method of manufacturing a digital access storage device according to claim 43 wherein the electronic control system is selected and structured so that the electronic functionality of the second disk drive is embedded in the electronic functionality of the first disk drive.

47. A method of manufacturing a digital access storage device according to claim 39 wherein the second disk drive is structured to function as an embedded memory component of the first disk drive.

48. A method of manufacturing a digital access storage device according to claim 39 wherein the second disk drive is selected to comprise a microdrive and wherein the electronic control system is structured to comprise a compact flash microdrive controller and a compact flash microdrive interface for controlling the second disk drive.

49. A digital access storage device comprising:

a first disk drive;

at least one second disk drive, wherein said second disk drive being smaller than said first disk drive, said second drive having a data transfer rate less than or equal to the data transfer rate of said first drive; and

an electronic control system interconnecting said first and second disk drives;

wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks; and

throughput data of the device comprises stripes of data from both the first and second disk drives;

wherein the electronic control system comprises a shared system control processor structured to adjust the length of the stripes of data from the first and second disk drives so the throughput data flow of the device is constant;

wherein the shared system control processor is structured so that the second disk drive provides throughput data during the seek operation of the first disk drive.

50. A digital access storage system comprising:

a first disk drive having a pre-determined size;

at least one second disk drive, said second disk drive being smaller than the first disk drive, said second drive having a data transfer rate less than or equal to the data transfer rate of said first drive;

an electronic control system interconnecting said first and second disk drive; and

wherein said drives are physically mounted on a common chassis;

wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks; and

throughput data of the device comprises stripes of data from both the first and second disk drives;

wherein the electronic control system comprises a shared system control processor structured to adjust the length of the stripes of data from the first and second disk drives so the throughput data flow of the device is constant;

wherein the shared system control processor is structured so that the second disk drive provides throughput data during the seek operation of the first disk drive.

51. A method of manufacturing a digital access storage device comprising steps of:

providing a first disk drive;

providing at least one second disk drive, said second disk drive being smaller than the first disk drive, said second drive having a data transfer rate less than or equal to the data transfer rate of said first drive; and

providing an electronic control system interconnecting said first disk drive and said second disk drive;

wherein the electronic control system is structured so that the first disk drive and at least one second disk drive function as a redundant array of independent disks; and

throughput data of the device comprises stripes of data from both the first and second disk drives;

wherein the electronic control system comprises a shared system control processor structured to adjust the length of the stripes of data from the first and second disk drives so the throughput data flow of the device is constant;

wherein the shared system control processor is structured so that the second disk drive provides throughput data during the seek operation of the first disk drive.