Method of increasing performance and manageablity of network storage systems using optimized cache setting and handling policies

• US 20040034746A1
• Filed: 08/11/2003
• Published: 02/19/2004
• Est. Priority Date: 08/19/2002
• Status: Active Grant

• Current Assignee: Adaptec Incorporated (Steel Partners Holdings LP)
• Original Assignee: Aristos Logic Corp. (Steel Partners Holdings LP)
• Inventors: Horn, Robert L., Acosta, Marc E.
• Granted Patent: US 7,353,334 B2
• Time in Patent Office: Days
• US Class Current: 711/141
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache

Abstract

A system for and method of increasing performance and manageability of storage area networks using optimized cache setting and handling policies. Initial cache management policies are set on a volume or zone basis, performance statistics are gathered based on preset statistical criteria, and policies are then set according to the goal of reaching particular system performance goals. Cache performance is optimized by customizing individual cache policies according to the underlying processing needs of each volume or sub-volume within the networked storage system. Cache parameter settings are optimized in a different way depending on whether the bulk of commands processed in the volume or sub-volume are pseudo-sequential or random, as well as other system-specific considerations.

Claims

1. A method for configuring a cache memory for a storage area network, comprising:

choosing a cache policy for at least a portion of a storage volume of said storage area network;

determining an address range of said portion of a storage volume;

constructing a command packet, wherein said command packet includes said cache policy and said address range;

sending said command packet to a cache controller of said storage area network; and

configuring said cache controller to operate the cache memory in accordance with said cache policy with respect to said portion of a storage volume.

2. The method of claim 1, wherein said steps of choosing, determining, constructing, and sending are performed from an administrative entity of said storage area network.

3. The method of claim 2, wherein said administrative entity comprises an storage network system administrator.

4. The method of claim 2, wherein said administrative entity comprises an automated cache tuning program.

5. The method of claim 1, wherein said step of choosing further comprises:

determining a plurality of cache operation parameters, wherein said plurality of cache operation parameters improves cache performance for one of a plurality of a predetermined access patterns.

6. The method of claim 5, wherein said plurality of predetermined access patterns includes sequential reading, sequential writing, random reading, random reading, and random writing.

7. A method for operating a cache memory in a storage area network, comprising:

receiving a host access command;

determining at least one storage volume or portion thereof associated with said host access command;

retrieving a set of cache operation parameters associated with said one storage volume or portion thereof; and

accessing said one storage volume or portion thereof while operating said cache memory in accordance with said set of cache operation parameters.

8. The method of claim 7, wherein said step of determining comprises:

determining an address range associated with said host command; and

choosing a set of volumes, or portion thereof, which is associated with said address range.

9. The method of claim 7, wherein said set of cache parameters include a parameter controlling how many sectors ahead of an address range associated with the host access command will be read.

10. The method of claim 7, wherein said set of cache parameters include a parameter controlling how many sectors before an address range associated with the host access command will be read.

11. A method of optimizing cache performance in a storage area network, comprising:

(a) setting an initial cache management policy for at least a portion of storage in said storage area network;

(b) operating said cache in accordance with said initial cache management policy for host command accessing said portion of storage, wherein said operating includes gathering cache operation statistics;

(c) determining whether a system performance goal has been met;

(d) if said system performance goal has not been met, determining a new cache management policy for said portion of storage, and repeating steps (a), (b), and (c) until said system performance goal has been met.

12. The method of claim 11, wherein said portion of storage comprises a single volume in said storage area network.

13. The method of claim 11, wherein said portion of storage comprises a portion of a single volume in said storage area network.

14. A storage area network, comprising:

a storage network having at least one volume of storage;

a cache memory;

a storage controller, coupled to said storage network and said cache memory, said storage controller comprising,

a host interface, for receiving from a host an access request with respect to a portion of said storage network;

a cache policy manager, coupled to said host interface; and

a cache parameter table coupled to said cache policy manager, for storing a set of cache parameters which comprise a cache policy, said cache parameter table storing a separate set of cache parameters for each set of volumes or a sub-volume of said storage network

wherein

said cache policy manager operates said cache memory in response to said access request by caching information transferred between said storage network and said host in accordance with the cache policy stored in said cache parameter table, the cache policy being associated with the set of volumes or the sub-volume of the storage network associated with said access request.

15. The storage area network of claim 14, further comprising:

an administrative entity;

wherein said administrative entity partitions said storage device into a plurality of volumes or sub-volumes, and sets a cache policy with respect to each one of said volumes or subvolumes.

16. The storage area network of claim 15, wherein said administrative entity is an storage network system administrator.

17. The storage area network of claim 15, wherein said administrative entity is an automated cache tuning program.

18. The storage area network of claim 15, wherein each cache policy stored in said cache parameter table improves cache performance for a particular type of access pattern.

19. The storage area network of claim 18, wherein said particular type of access pattern include sequential reads or write.

20. The storage area network of claim 15, wherein said particular type of access pattern include random reads or write.