Data storage within hybrid storage aggregate

• US 9,043,530 B1
• Filed: 04/09/2012
• Issued: 05/26/2015
• Est. Priority Date: 04/09/2012
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Sundaram, Rajesh, Kimmel, Jeffrey S., Prakash, Ashish, Doucette, Douglas Paul, Grunwald, David
• Primary Examiner(s): Rojas, Midys
• Application Number:
  US13/442,194
• Time in Patent Office: 1,142 Days
• Field of Search: None
• US Class Current: 711/100
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2212/1024 Latency reduction
• CPC Class Codes: G06F 2212/217 Hybrid disk, e.g. using both magnetic and solid state storage devices
• CPC Class Codes: G06F 2212/222 Non-volatile memory
• CPC Class Codes: G06F 2212/281 Single cache
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/068 Hybrid storage device
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays

Abstract

Among other things, one or more techniques and/or systems are provided for storing data within a hybrid storage aggregate comprising a lower-latency storage tier and a higher-latency storage tier. In particular, frequently accessed data, randomly accessed data, and/or short lived data may be stored (e.g., read caching and/or write caching) within the lower-latency storage tier. Infrequently accessed data and/or sequentially accessed data may be stored within the higher-latency storage tier. Because the hybrid storage aggregate may comprise a single logical container derived from the higher-latency storage tier and the lower-latency storage tier, additional storage and/or file system functionality may be implemented across the storage tiers. For example, deduplication functionality, caching functionality, backup/restore functionality, and/or other functionality may be provided through a single file system (or other type of arrangement) and/or a cache map implemented within the hybrid storage aggregate.

Claims

1. A method for storing data within a hybrid storage aggregate, comprising:

receiving an I/O operation associated with a hybrid storage aggregate comprising a lower-latency storage tier and a higher-latency storage tier;

evaluating the I/O operation to determine that the I/O operation comprises requested data corresponding to at least one of a non-sequential read operation for data within the higher-latency storage tier, data designated for low latency access, or a read operation for data predicted for frequent access;

retrieving the requested data from the higher-latency storage tier;

storing a copy of the requested data as copied data within the lower-latency storage tier;

maintaining a temperature metric for the copied data; and

if the temperature metric falls below a threshold, evicting the copied data from the lower-latency storage tier.

2. The method of claim 1, the lower-latency storage tier comprising electronic storage media and the higher-latency storage tier comprising magnetic storage media.

3. The method of claim 2, the electronic storage media comprising one or more solid state devices and the magnetic storage media comprising one or more hard disk drives.

4. The method of claim 1, the higher-latency storage tier comprising a first RAID group comprising magnetic storage media and the lower-latency storage tier comprising a second RAID group comprising electronic storage media.

5. The method of claim 4, the second RAID group non-disruptively added to the hybrid storage aggregate without interrupting access to the first RAID group.

6. The method of claim 1, comprising integrating one or more RAID groups into a file system of the hybrid storage aggregate, the one or more RAID groups associated with at least one of the higher-latency storage tier or the lower-latency storage tier.

7. The method of claim 1, the evaluating the I/O operation comprising:

determining that the requested data is to be accessed at random block offsets.

8. The method of claim 1, the storing a copy comprising:

making an entry into a cache map indicating that the copied data was stored within the lower-latency storage tier, the cache map comprising entries associated with respective copied data copied from the higher-latency storage tier to the lower-latency storage tier.

9. The method of claim 8, the cache map integrated into a file system of the hybrid storage aggregate.

10. The method of claim 1, the evicting comprising:

removing an entry within a cache map associated with the copied data.

11. The method of claim 1, the lower-latency storage tier maintained as a cache.

12. The method of claim 1, the retrieving the requested data comprising;

if a cached copy of the requested data is stored within the lower-latency storage tier, then retrieving the cached copy as the requested data, otherwise retrieving the requested data from the higher-latency storage tier.

13. The method of claim 1, the evaluating the I/O operation comprising:

determining that the I/O operation comprises a non-sequential hot read operation based upon determining that the requested data is accessed above a threshold frequency.

14. The method of claim 1, the storing a copy comprising:

maintaining the requested data within the higher-latency storage tier.

15. The method of claim 1, comprising:

storing metadata associated with the hybrid storage aggregate within the lower-latency storage tier.

16. A system for storing data within a hybrid storage aggregate, comprising:

a read caching component configured to;

receive an I/O operation associated with a hybrid storage aggregate comprising a lower-latency storage tier and a higher-latency storage tier;

evaluate the I/O operation to determine that the I/O operation comprises requested data corresponding to a non-sequential read operation for data within the higher-latency storage tier;

retrieve the requested data from the higher-latency storage tier;

store a copy of the requested data as copied data within the lower-latency storage tier;

maintain a temperature metric for the copied data; and

if the temperature metric falls below a threshold, evict the copied data from the lower-latency storage tier.

17. The system of claim 16, the lower-latency storage tier comprising electronic storage media and the higher-latency storage tier comprising magnetic storage media.

18. The system of claim 17, the hybrid storage aggregate comprising at least one first RAID group comprising at least some of the magnetic storage media and at least one second RAID group comprising at least some of the electronic storage media.

19. The system of claim 16, the read caching component configured to:

make an entry into a cache map indicating that the copied data was stored within the lower-latency storage tier, the cache map comprising entries associated with respective copied data copied from the higher-latency storage tier to the lower-latency storage tier.

20. The system of claim 19, the cache map integrated into a file system of the hybrid storage aggregate.

21. The system of claim 16, the read caching component configured to at least one of:

determine that the requested data is to be accessed non-sequentially;

or

determine that the requested data is accessed above a threshold frequency.

22. The system of claim 16, the read caching component comprised within a node configured to manage storage of data within the hybrid storage aggregate.

23. The system of claim 16, the read caching component configured to:

remove an entry within a cache map associated with the copied data responsive to evicting the copied data.