Dynamic input/output optimization within a storage controller

A storage controller for optimizing accesses to a plurality of physical storage devices, the storage controller comprising:

• a memory, configured to store:
• information from I/O requests, wherein each of the I/O requests specifies one of the plurality of physical storage devices to be accessed, wherein the information specifies a location to be accessed on the specified physical storage device;
• and
• an access profile for each the plurality of physical storage devices, wherein each of the access profiles indicates whether the recent I/O requests to the physical storage device are sequential or random;
• and
• a microprocessor, coupled to said memory, operable to:
• populate the access profile for each of the plurality of physical storage devices based on the information related to the I/O requests information stored in the memory;
• and
• cause each of the plurality of physical storage devices to be accessed using a first command queue depth if its access profile indicates sequential and using a second command queue depth if its access profile indicates random, wherein the first command queue depth is less than the second command queue depth.

A method for a storage controller to access a physical storage device based on a history of commands issued to the physical storage device, the method comprising:

• storing address information in memory for a plurality of temporally consecutive commands to the physical storage device;
• sampling the address information after new address information has been stored;
• dynamically updating an access profile for the physical storage device between sequential and random states, based on predetermined conditions;
• issuing a plurality of commands to the physical storage device with a varying command queue depth, depending upon the access profile, wherein the command queue depth is the number of concurrent commands the storage controller is allowed to issue to the physical storage device;
• and
• causing each of the plurality of physical storage devices to be accessed using a first command queue depth if its access profile indicates sequential and using a second command queue depth if its access profile indicates random, wherein the first command queue depth is less than the second command queue depth.