Virtual disk drive system and method

• US 7,941,695 B2
• Filed: 02/04/2009
• Issued: 05/10/2011
• 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:
  US12/365,461
• Publication Number:
  US 20090138755A1
• Time in Patent Office: 825 Days
• Field of Search: 714/3, 714 6- 10, 714/13, 714/15, 714/16, 714/20, 714/21, 714 37- 39, 714/42, 714/43, 714/54
• US Class Current: 714/6.12
• 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 data space blocks from a plurality of data storage devices;

generating a snapshot of data for the abstract volume;

storing an address index for the snapshot;

accessing the snapshot via the stored address index;

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; and

modifying the temporary volume without modifying the underlying data in the snapshot and the abstract volume.

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

3. The method of claim 1, wherein the snapshot is application initiated.

4. The method of claim 1, wherein generating the snapshot of data for the abstract volume comprises recording write operations to the abstract volume.

5. The method of claim 1, wherein generating a snapshot of data for the abstract volume comprises tracking changes to the abstract volume.

6. The method of claim 5, wherein tracking changes to the abstract volume comprises maintaining at least a partial list of delta writes to the abstract volume.

7. The method of claim 6, wherein the at least a partial list comprises the last writes to the single data addresses of the abstract volume since a previous snapshot was generated.

8. The method of claim 1, 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.

9. The method of claim 1, 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.

10. The method of claim 1, wherein the temporary volume is used for backup of the data by replicating the data.

11. The method of claim 1, wherein the temporary volume is used for data recovery.

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

a data storage system having an abstraction of data space blocks; and

a data manager having at least one data storage system controller, the system controller configured for;

generating a snapshot of the abstraction of data space blocks;

storing an address index of the snapshot of the abstraction of data space blocks;

accessing the snapshot via the stored address index;

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; and

modifying the temporary volume without modifying the underlying data in the snapshot and the abstract volume.

13. The system of claim 12, wherein the system controller automatically generates snapshots of the abstraction of data space blocks at predetermined time intervals.

14. The system of claim 12, wherein the system controller automatically generates a snapshot of the abstraction of data space blocks based on application control.

15. The system of claim 12, wherein the system controller records write operations to the abstraction of data space blocks.

16. The system of claim 15, wherein the system controller maintains at least a partial list of delta writes to the abstraction of data space blocks.

17. The system of claim 16, wherein the at least a partial list comprises the last writes to the single data addresses of the abstraction of data space blocks since a previous snapshot was generated.

18. The system of claim 12, wherein the controller uses the temporary volume for data recovery.

19. The system of claim 12, wherein the system controller tracks changes to the abstraction of data space blocks.