Virtual disk drive system and method

• US 7,493,514 B2
• Filed: 03/22/2007
• Issued: 02/17/2009
• 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:
  US11/689,899
• Publication Number:
  US 20070234110A1
• Time in Patent Office: 698 Days
• Field of Search: 714 6- 8, 714/13, 714/15, 714/16, 714/20, 714/42
• US Class Current: 714/6.22
• 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 method of data instant replay, comprising the steps of:

creating an abstract volume of disk space blocks from a plurality of RAID devices;

allocating the disk space blocks of the abstract volume;

writing data to the allocated disk space blocks;

generating a snapshot for the abstract volume;

storing an address index of the snapshot; and

accessing the snapshot via the stored address index.

2. The method of claim 1, wherein the snapshot is generated at predetermined time intervals.

3. The method of claim 1, further comprising creating a temporary volume based on the snapshot that provides a view of the contents of the abstract volume at a past point in time.

4. The method of claim 3, further comprising modifying the temporary volume.

5. The method of claim 4, further comprising generating a second snapshot for the temporary volume and storing an address index of the second snapshot.

6. The method of claim 3, wherein the temporary volume is used for testing, such that the testing may be performed on data as it was at the past point in time without altering the underlying data in the abstract volume.

7. The method of claim 6, wherein the temporary volume is used for remote testing.

8. The method of claim 3, wherein the temporary volume is used for training, such that the training may be performed on data as it was at the past point in time without altering the underlying data in the abstract volume.

9. The method of claim 3, wherein the temporary volume is used for backup of the data by replicating the data.

10. The method of claim 9, wherein the data is replicated remotely.

11. The method of claim 3, wherein the temporary volume is used for data recovery.

12. The method of claim 3, wherein write operations may be performed on the temporary volume without modifying the underlying data in the snapshot and the abstract volume.

13. A method of data instant replay, comprising the steps of:

defining a default size of disk space of a RAID subsystem which forms a pool of storage;

allocating the pool of storage;

writing data to the allocated pool of storage;

generating a snapshot for the pool of storage;

storing an address index of the snapshot; and

accessing the snapshot via the stored address index.

14. The method of claim 13, further comprising creating a temporary pool of storage based on the snapshot that provides a view of the contents of the pool of storage at a specified past point in time.

15. The method of claim 14, wherein write operations may be performed on the temporary pool of storage without modifying the underlying data in the snapshot and the original pool of storage.

16. The method of claim 13, wherein the temporary pool of storage is used for at least one of testing and training, such that the testing and training may be performed on data as it was at the past point in time without altering the underlying data in the pool of storage.

17. The method of claim 13, wherein the temporary pool of storage is used for backup of the data by replicating the data.

18. The method of claim 13, wherein the temporary pool of storage is used for data recovery.

19. A disk drive system, capable of replaying data, comprising:

abstract means for generating at least one abstraction of disk space blocks from a plurality of RAID devices;

allocating means for allocating the disk space blocks of the abstraction;

writing means for writing data to the allocated disk space blocks;

fusing means for generating a snapshot for the abstraction;

storing means for storing an address index of the snapshot; and

accessing means for accessing the snapshot via the stored address index.