Automatic I/O stream selection for storage devices

1. A method of selecting among a plurality of I/O streams through which data is to be written to a multi-streaming flash storage device, each I/O stream corresponding to a different logical division of the multi-streaming flash storage device, the method comprising:

assigning write sequences to I/O streams according to length of write sequences;

receiving instructions for a write operation, the instructions including a starting logical block address (LBA) and a number of blocks of data to be written;

determining whether the write operation is part of an existing write sequence;

identifying an I/O stream associated with an existing write sequence; and

providing a stream ID of the identified I/O stream to the multi-streaming flash storage device,

wherein assigning write sequences to I/O streams according to length includes:

providing a number of queues, each queue including a plurality of elements, each element configured to store a last LBA of a current write sequence and a count value; and

assigning each queue in hierarchal order to a corresponding one of the I/O streams,

wherein assigning write sequences to I/O streams according to length further includes:

comparing the count value with an upgrade threshold value;

storing the last LBA of the current write sequence and the count value in an element of a first queue in response to determining that the count value is less than the upgrade threshold value; and

storing the last LBA of the current write sequence and the count value in an element of a second queue in response to determining that the count value is greater than the upgrade threshold value, wherein the second queue is in a next higher hierarchal order than the first queue.

2. The method of claim 1 , wherein assigning write sequences to I/O streams according to length further includes moving the element of the first queue to the front of the first queue.

3. The method of claim 1 , wherein the count value is calculated as an accumulating function of a number of blocks of data written in the current write sequence.

4. The method of claim 1 , wherein determining whether the write operation is part of an existing write sequence includes:

determining whether the starting LBA is within a threshold proximity of a last LBA stored in an element of the queues.

5. A method of selecting among a plurality of I/O streams through which data is to be written to a multi-streaming flash storage device, each I/O stream corresponding to a different logical division of the multi-streaming flash storage device, the method comprising:

assigning write sequences to I/O streams according to length of write sequences;

receiving instructions for a write operation, the instructions including a starting logical block address (LBA) and a number of blocks of data to be written;

determining whether the write operation is part of an existing write sequence;

identifying an I/O stream associated with an existing write sequence; and

providing a stream ID of the identified I/O stream to the multi-streaming flash storage device,

wherein assigning write sequences to I/O streams according to length includes:

providing a number of queues, each queue including a plurality of elements, each element configured to store a last LBA of a current write sequence and a count value; and

assigning each queue in hierarchal order to a corresponding one of the I/O streams,

wherein determining whether the write operation is part of an existing write sequence includes: determining whether the starting LB A is within a threshold proximity of a last LBA stored in an element of the queues, and

wherein determining whether the write operation is part of an existing write sequence further includes:

summing the starting LBA and the number of blocks of data to be written;

calculating the count value as a function of the number of blocks of data to be written; and

storing the sum as the last LBA and the count value in the first element of a lowest ordered queue.

6. The method of claim 1 , wherein identifying an I/O stream associated with an existing write sequence includes:

identifying a queue in which the last LBA and the count value of the current write sequence is to be stored.

7. The method of claim 6 , wherein providing a stream ID of the identified I/O stream to the multi-streaming flash storage device includes:

returning a number associated with the hierarchal order of the identified queue as the stream ID.

8. A non-transitory, tangible computer readable storage medium having stored thereon computer executable instructions that, when executed by a computer, cause the computer to select among a plurality of I/O streams through which data is to be written to a multi-streaming flash storage device, each I/O stream corresponding to a different storage area of the multi-streaming flash storage device, by:

assigning write sequences to I/O streams according to length of write sequences;

receiving instructions for a write operation, the instructions including a starting logical block address (LBA) and a number of blocks of data to be written;

determining whether the write operation is part of an existing write sequence;

identifying an I/O stream associated with an existing write sequence; and

providing a stream ID of the identified I/O stream to the multi-streaming flash storage device,

wherein assigning write sequences to I/O streams according to length includes:

providing a number of queues, each queue including a plurality of elements, each element configured to store a last LBA of a current write sequence and a count value; and

assigning each queue in hierarchal order to a corresponding one of the I/O streams,

wherein assigning write sequences to I/O streams according to length further includes:

comparing the count value with an upgrade threshold value;

storing the last LBA of the current write sequence and the count value in an element of a first queue in response to determining that the count value is less than the upgrade threshold value; and

storing the last LBA of the current write sequence and the count value in an element of a second queue in response to determining that the count value is greater than the upgrade threshold value, wherein the second queue is in a next higher hierarchal order than the first queue.

9. The non-transitory, tangible computer readable storage medium of claim 8 , wherein assigning write sequences to I/O streams according to length further includes moving the element of the first queue to the front of the first queue.

10. The non-transitory, tangible computer readable storage medium of claim 8 , wherein the count value is calculated as an accumulating function of a number of blocks of data written in the current write sequence.

11. The non-transitory, tangible computer readable storage medium of claim 8 , wherein determining whether the write operation is part of an existing write sequence includes:

determining whether the starting LBA is within a threshold proximity of a last LBA stored in an element of the queues.

12. The non-transitory, tangible computer readable storage medium of claim 11 , wherein determining whether the write operation is part of an existing write sequence further includes:

summing the starting LBA and the number of blocks of data to be written;

calculating the count value as a function of the number of blocks of data to be written; and

storing the sum as the last LBA and the count value in the first element of a lowest ordered queue.

13. The non-transitory, tangible computer readable storage medium of claim 8 , wherein identifying an I/O stream associated with an existing write sequence includes:

identifying a queue in which the last LBA and the count value of the current write sequence is to be stored.

14. The non-transitory, tangible computer readable storage medium of claim 13 , wherein providing a stream ID of the identified I/O stream to the multi-streaming flash storage device includes:

returning a number associated with the hierarchal order of the identified queue as the stream ID.

15. The non-transitory, tangible computer readable storage medium of claim 8 , wherein the instructions are executed in a kernel of an operating system running on the computer.

16. The non-transitory, tangible computer readable storage medium of claim 8 , wherein the instructions are executed by a virtual machine software running on the computer.