Dynamically upgradeable fault-tolerant storage system permitting variously sized storage devices and method

• US 20060143380A1
• Filed: 11/04/2005
• Published: 06/29/2006
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: Storcentric DIP Lender LLC
• Original Assignee: Data Robotics Incorporated
• Inventors: Terry, Julian M., Barrall, Geoffrey S.
• Granted Patent: US 7,814,272 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1084 Degraded mode, e.g. caused by single or multiple storage removals or disk failures
• CPC Class Codes: G06F 11/1096 Parity calculation or recalculation after configuration or reconfiguration of the system
• CPC Class Codes: G06F 11/1658 Data re-synchronization of a redundant component, or initial sync of replacement, additional or spare unit
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2087 with a common controller
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 11/325 by lamps or LED's
• CPC Class Codes: G06F 2211/1004 Adaptive RAID, i.e. RAID system adapts to changing circumstances, e.g. RAID1 becomes RAID5 as disks fill up
• CPC Class Codes: G06F 2211/1023 Different size disks, i.e. non uniform size of disks in RAID systems with parity
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G11B 2220/415 Redundant array of inexpensive disks [RAID] systems
• CPC Class Codes: G11B 2220/65 wherein solid state memory is used for storing indexing information or metadata
• CPC Class Codes: G11B 27/11 by using information not detectable on the record carrier
• CPC Class Codes: G11B 27/329 on a disc [VTOC]

Abstract

A dynamically upgradeable fault-tolerant storage system permits a storage device to be replaced with a larger storage device. Data stored redundantly across multiple storage devices is reproduced on the replacement device, and the additional storage space on the replacement device is made available for redundantly storing additional data.

Claims

1. A method of storing data in a set of storage devices, the set having at least two devices, so as to permit replacement of a first one of the devices with a replacement device having larger storage capacity without data loss, the method comprising:

storing the data redundantly in the set of storage devices;

on replacement of the first one of the devices by the replacement device, reproducing on the replacement device, the data that was stored on the first device, using the data stored redundantly on at least one other drive of the set; and

making storage capacity remaining on the replacement drive available for storage of additional data, in a manner that the additional data is stored redundantly, using at least one redundancy scheme.

2. A method according to claim 1, wherein storing the data redundantly in the set of storage devices comprises:

storing the data using a mixture of redundancy schemes.

3. A method according to claim 2, wherein the redundancy schemes are selected from the group including mirroring, striping with parity, RAID6, dual parity, diagonal Parity, Low Density Parity Check codes, and turbo codes.

4. A method according to claim 1, further comprising:

storing said additional data redundantly within said storage capacity remaining on said replacement device, if no other device has a sufficient amount of available storage capacity to provide redundancy for said additional data.

5. A method according to claim 4, wherein storing said additional data redundantly within said storage capacity remaining on said replacement device comprises mirroring.

6. A method according to claim 1, further comprising:

storing said additional data redundantly across multiple storage devices including said replacement device, if at least one other device has a sufficient amount of available storage capacity to provide redundancy for said additional data.

7. A method according to claim 6, wherein storing said additional data redundantly across multiple storage devices comprises at least one of mirroring, striping with parity, RAID6, dual parity, diagonal Parity, Low Density Parity Check codes, and turbo codes.

8. A method according to claim 1, further comprising:

advertising a first storage capacity for the set of storage devices greater than an actual storage capacity for the set of storage devices; and

mapping requests to store data in locations outside of the actual storage capacity to locations within the actual storage capacity.

9. A method according to claim 8, wherein mapping requests comprises:

maintaining a lookup table mapping requested locations to actual locations; and

indexing the lookup table according to the requested location to obtain the actual location.

10. A storage system comprising:

a plurality of storage device slots for receiving storage devices of various storage capacities; and

a storage manager operably coupled to the plurality of storage device slots for managing a set of storage devices coupled thereto, the storage manager storing data on the set of storage devices in a redundant manner and, on replacement of a first one of the devices by a replacement device having larger storage capacity, reproducing on the replacement device, the data that was stored on the first device, using the data stored redundantly on other drives of the set, the storage manager further making the added storage capacity available for storage of additional data, in a manner that the additional data is stored redundantly, using at least one redundancy scheme.

11. A storage system according to claim 10, wherein the storage manager stores the data using a mixture of redundancy schemes.

12. A storage system according to claim 11, wherein the redundancy schemes are selected from the group including mirroring, striping with parity, RAID6, dual parity, diagonal Parity, Low Density Parity Check codes, and turbo codes.

13. A storage system according to claim 10, wherein the storage manager stores said additional data redundantly within said storage capacity remaining on said replacement device, if no other device has a sufficient amount of available storage capacity to provide redundancy for said additional data.

14. A storage system according to claim 13, wherein the storage manager stores said additional data redundantly within said storage capacity remaining on said replacement device using mirroring.

15. A storage system according to claim 10, wherein the storage manager stores said additional data redundantly across multiple storage devices including said replacement device, if at least one other device has a sufficient amount of available storage capacity to provide redundancy for said additional data.

16. A storage system according to claim 15, wherein the storage manager stores said additional data redundantly across multiple storage devices using at least one of mirroring, striping with parity, RAID6, dual parity, diagonal Parity, Low Density Parity Check codes, and turbo codes.

17. A storage system according to claim 10, wherein the storage manager advertises a first storage capacity for the set of storage devices greater than an actual storage capacity of the set of storage devices and maps requests to store data in locations outside of the actual storage capacity to locations within the actual storage capacity.

18. A storage system according to claim 17, further comprising:

a lookup table maintained by the storage manager for mapping requested locations to actual locations, wherein the storage manager indexes the lookup table according to the requested location to obtain the actual location.

19. A storage system comprising:

a plurality of storage devices; and

a storage manager operably coupled to the plurality of storage devices, wherein the storage manager stores data redundantly in the plurality of storage devices and, upon replacement of a first storage device with a replacement storage device of larger storage capacity, automatically reconfigures existing data across the plurality of storage devices so as to at least maintain and optionally enhance redundancy and make additional storage capacity, provided by the replacement storage device, available for redundant storage.

20. A storage system according to claim 19, wherein the storage manager reproduces on the replacement device, the data that was stored on the first device, using the data stored redundantly on other storage devices.

21. A storage system according to claim 19, wherein the storage manager reconfigures the data using additional storage capacity provided by the replacement storage device so as to enhance redundancy for the data.

22. A storage system according to claim 20, wherein the storage manager stores the data using a first set of redundancy schemes and reconfigures the data using a second set of redundancy schemes that may be different than the first set of redundancy schemes.