Virtual disk drive system and method

• US 7,613,945 B2
• Filed: 08/13/2004
• Issued: 11/03/2009
• Est. Priority Date: 08/14/2003
• Status: Active Grant

• Current Assignee: Dell International LLC (Dell Technologies Inc.)
• Original Assignee: Compellent Technologies Incorporated (Dell Technologies Inc.)
• Inventors: Klemm, Michael J., Soran, Philip E., Guider, John P., Aszmann, Lawrence E.
• Primary Examiner(s): Iqbal; Nadeem
• Application Number:
  US10/918,329
• Publication Number:
  US 20050055603A1
• Time in Patent Office: 1,908 Days
• Field of Search: 714/5, 714/6, 714/13, 714/15
• US Class Current: 714/5.11
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1461 Backup scheduling policy
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 12/02 Addressing or allocation; Relocation program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A disk drive system and method capable of dynamically allocating data is provided. The disk drive system may include a RAID subsystem having a pool of storage, for example a page pool of storage that maintains a free list of RAIDs, or a matrix of disk storage blocks that maintain a null list of RAIDs, and a disk manager having at least one disk storage system controller. The RAID subsystem and disk manager dynamically allocate data across the pool of storage and a plurality of disk drives based on RAID-to-disk mapping. The RAID subsystem and disk manager determine whether additional disk drives are required, and a notification is sent if the additional disk drives are required. Dynamic data allocation and data progression allow a user to acquire a disk drive later in time when it is needed. Dynamic data allocation also allows efficient data storage of snapshots/point-in-time copies of virtual volume pool of storage, instant data replay and data instant fusion for data backup, recovery etc., remote data storage, and data progression, etc.

Claims

1. A disk drive system, capable of dynamically allocating data in a pool of storage, comprising:

a RAID subsystem;

a plurality of virtual volumes comprising disk space blocks from the RAID subsystem, wherein at least a portion of the plurality of virtual volumes each comprise disk space blocks from a plurality of RAID devices; and

a disk manager having at least one disk storage system controller;

wherein the disk manager is configured to;

maintain a pool of storage comprising a list of free disk space blocks of the RAID subsystem;

dynamically allocate the free disk space blocks to the plurality of virtual volumes; and

write data to the allocated disk space blocks.

2. The system of claim 1, wherein the RAID subsystem and the disk manager determine whether additional disk drives are required, and a notification is sent if the additional disk drives are required.

3. The system of claim 1, wherein the disk manager manages a plurality of disk storage system controllers.

4. The system of claim 3, further comprising a plurality of redundant disk storage system controllers to cover failure of an operated disk storage system controller.

5. The system of claim 1, wherein the RAID subsystem further comprises a combination of at least one of RAID types RAID-0, RAID-1, RAID-5, and RAID-10.

6. The system of claim 5, further comprising RAID types RAID-3, RAID-4, RAID-6, and RAID-7.

12. The system of claim 1, wherein the at least one disk storage system controller automatically generates a snapshot for each of the plurality of virtual volumes at predetermined time intervals and stores an address index of each snapshot in an associated virtual volume such that the snapshot of the virtual volume can be instantly located via a stored address index, wherein the snapshot comprises changes to data in an associated virtual volume that have taken place since a previous snapshot taken at a previous time interval.

20. The system of claim 1, wherein the at least one disk storage system controller automatically generates a snapshot for each of the plurality of virtual volumes, stores an address index of each snapshot, accesses at least one of the snapshots via the stored address index, and creates a temporary volume from each of the at least one of the snapshots based on the at least one of the snapshots that provides a view of contents of an associated virtual volume at a first point in time, wherein the snapshots comprise changes to data in an associated virtual volume that have taken place since a previous snapshot taken at a second past point in time.

7. A method of dynamically allocating data of a RAID storage system, comprising the steps of:

generating a plurality of virtual volumes of disk space blocks from a plurality of RAID devices, wherein at least a portion of the plurality of virtual volumes each comprise disk space blocks from more than one of the plurality of RAID devices;

managing a page pool of storage that maintains a list of free disk space blocks of the plurality of RAID devices;

dynamically allocating the disk space blocks of the plurality of RAID devices to the plurality of virtual volumes using the page pool of storage; and

writing data to the allocated disk space blocks.

8. The method of claim 7, further comprising setting a size of the disk space blocks as a default and changeable by a user.

9. The method of claim 7, further comprising:

determining whether additional disk drives for the RAID storage system are required; and

sending a notification if the additional disk drives are required.

10. The method of claim 9, further comprising sending notification via an email.

11. The method of claim 7, wherein the plurality of virtual volumes comprise disk space blocks from at least one of a plurality of RAID types RAID-0, RAID-1, RAID-5, and RAID-10.

13. The method of claim 7 further comprising automatically generating a snapshot for each of the plurality of virtual volumes at predetermined time intervals, wherein each snapshot comprises changes to the data in an associated virtual volume that have taken place since a previous snapshot taken at a previous time interval and storing an address index of each snapshot such that each snapshot of the plurality of virtual volumes can be instantly located via the stored address index.

14. The method of claim 13, wherein each snapshot comprises a record of write operations to an associated virtual volume.

15. The method of claim 13, wherein the predetermined time intervals are user defined.

16. The method of claim 13, wherein the time intervals are in a range of every few minutes to every few hours.

17. The method of claim 13, wherein the snapshots are stored at a remote RAID subsystem such that if a major system crash occurs, integrity of data is not affected, and the data can be instantly recovered.

18. The method of claim 13, further comprising generating a snapshot for at least one virtual volume upon a user request.

19. The method of claim 13, further comprising coalescing at least two snapshots for an associated virtual volume.

21. The method of claim 7 further comprising:

generating a plurality of snapshots for the virtual volumes;

storing address indexes of the snapshots;

accessing at least one of the plurality of snapshots via the stored address index; and

creating a temporary volume from each of the at least one of the snapshots based on the at least one of the snapshots that provides a view of contents of an associated virtual volume at a point in time.

22. The method of claim 21, wherein the snapshots are generated at predetermined time intervals.

23. The method of claim 21, further comprising modifying the temporary volume without altering underlying data of the virtual volume.

24. The method of claim 21, wherein the temporary volume is used for testing, and the testing is performed on data as it was at the point in time without altering underlying data in the virtual volume.

25. The method of claim 21, wherein the temporary volume is used for training, and the training is performed on data as it was at the point in time without altering underlying data in the virtual volume.

26. The method of claim 21, wherein the temporary volume is used for backup of the data.

27. The method of claim 21, wherein the temporary volume is used for data recovery.