Data storage management in a memory device

1. A disc drive comprising:

a first cache memory, wherein the first cache memory is a media cache that is a portion of non-volatile data storage media that include final physical destination locations for data packets received in the disc drive, wherein the non-volatile data storage media comprise one or more non-volatile data storage discs, and wherein the first cache memory is a portion of the one or more non-volatile data storage discs;

a volatile cache memory;

a non-volatile cache memory of a different type than the first cache memory, the non-volatile cache memory being physically separate from the data storage media; and

a controller configured to:

temporarily store at least some of the received data packets in the non-volatile cache memory;

when the at least some of the received data packets reach a predetermined number of data packets in the non-volatile cache memory, transfer the predetermined number of data packets from the non-volatile cache memory to the first cache memory prior to storing the predetermined number of data packets in at least some of the final physical destination locations in the disc drive;

group the predetermined number of data packets transferred to the first cache memory into different subsets based on proximity of logical block addresses of different one of the predetermined number of data packets, wherein the first cache memory is the portion of the one or more non-volatile data storage discs;

transfer any one of the subsets of data packets from said first cache memory, which is the portion of the one or more non-volatile data storage discs, to the volatile cache memory, and transfer any existing data in the final physical destination locations for the subset to the volatile cache memory;

update the transferred existing data with the data packets of the subset in the volatile cache memory to obtain modified data; and

commit the modified data to the final physical destination locations for the subset.

2. The disc drive of claim 1 and wherein each of the at least some of the received data packets has a size that is different from an allocated storage capacity of each of the at least some of the final physical destination locations.

3. The disc drive of claim 2 and wherein received data packets other than the at least some of the received data packets each have a size that corresponds to the allocated storage capacity of each of the final physical destination locations.

4. The disc drive of claim 3 and wherein the controller is further configured to:

temporarily store each received data packet, which has the size that corresponds to the allocated storage capacity of the final physical destination location, in the volatile cache memory; and

directly transfer the temporarily stored received data packets, which each has the size that corresponds to the allocated storage capacity of the final physical destination location, form the volatile cache memory to the intended final physical destination locations.

5. The disc drive of claim 3 and wherein the controller is further configured to:

temporarily store each received data packet, which has the size that corresponds to the allocated storage capacity of the final physical destination location, in the non-volatile cache memory; and

directly transfer the temporarily stored received data packets, which each has the size that corresponds to the allocated storage capacity of the final physical destination location, from the non-volatile cache memory to the intended final physical destination locations.

6. The disc drive of claim 1 and wherein the non-volatile cache memory is a solid state memory.

7. The disc drive of claim 6 and wherein the non-volatile cache memory has a substantially lower capacity than the volatile cache memory.

8. The disc drive of claim 1 and wherein the data storage media are one of magnetic storage media or optical storage media.

9. The disc drive of claim 1 and wherein the data packets are addressed by logical block addresses (LBAs).

10. The disc drive of claim 1 and wherein the non-volatile cache memory is as rewritable as the data storage media.

11. A method implemented in a disc drive, the method comprising:

providing a first cache memory, wherein the first cache memory is a media cache that is a portion of non-volatile data storage media that include final physical destination locations for data packets received in the disc drive, wherein the non-volatile data storage media comprises one or more non-volatile data storage discs, and wherein the first cache memory is a portion of the one or more non-volatile data storage discs;

providing a volatile cache memory;

providing a non-volatile cache memory of a different type than the first cache memory, the non-volatile cache memory being physically separate from the data storage media;

temporarily storing at least some of the received data packets in the non-volatile cache memory;

when the at least some of the received data packets reach a predetermined number of data packets in the non-volatile cache memory, transferring the predetermined number of data packets from the non-volatile cache memory to the first cache memory prior to storing the predetermined number of data packets in at least some of the final physical destination locations in the disc drive;

grouping the predetermined number of data packets transferred to the first cache memory into different subsets based on proximity of logical block addresses of different ones of the predetermined number of data packets, wherein the first cache memory is the portion of the one or more non-volatile data storage discs;

transferring any one of the subsets of data packets from said first cache memory, which is the portion of the one or more non-volatile data storage discs, to the volatile cache memory, and transferring any existing data in the final physical destination locations for the subset to the volatile cache memory;

updating the transferred existing data with the data packets of the subset in the volatile cache memory to obtain modified data; and

committing the modified data to the final physical destination locations for the subset.

12. The method of claim 11 and wherein each of the at least some of the received data packets has a size that is different from an allocated storage capacity of each of the at least some of the final physical destination locations.

13. The method of claim 12 and wherein received data packets other than the at least some of the received data packets each have a size that corresponds to the allocated storage capacity of each of the final physical destination locations.

14. The method of claim 13 and further comprising:

temporarily storing each received data packet, which has the size that corresponds to the allocated storage capacity of the final physical destination location, in the volatile cache memory; and

directly transferring the temporarily stored received data packets, which each has the size the corresponds to the allocated storage capacity of the final physical destination location, from the volatile cache memory to the intended final physical destination locations.

15. The method of claim 13 and further comprising:

temporarily storing each received data packet, which has the size that corresponds to the allocated storage capacity of the final physical destination location, in the non-volatile cache memory; and

directly transferring the temporarily stored received data packets, which each has the size that correspond to the allocated storage capacity of the final physical destination location, from the non-volatile cache memory to the intended final physical destination location.

16. The method of claim 11 and wherein providing the non-volatile cache memory includes providing a non-volatile solid state cache memory.

17. The method of claim 16 and wherein the non-volatile cache memory has a substantially lower capacity than the volatile cache memory.

18. The method of claim 11 and wherein the data storage media are one of magnetic storage media or optical storage media.

19. The method of claim 11 and further comprising addressing the data packets by logical block addresses (LBAs).

20. The method of claim 11 and wherein the non-volatile cache memory is as rewritable as the data storage media.