Dynamic adjustment of read/write ratio of a disk cache

A computer program product including computer usable program code embodied on a non-transitory computer readable storage medium, the computer program product comprising:

• computer usable program code for writing to a primary region of a cache that is split into a read portion and write portion and for writing to a sample region of the cache that is split into a read portion and a write portion, wherein a read/write area ratio of the sample region is different than a read/write area ratio of the primary region;
• computer usable program code for caching reads and writes from a hard disk such that each cached read is located at the read portion of the sample region or primary region and each cached write is at the write portion of the sample region or primary region;
• computer usable program code for tracking the performance of the primary region and the performance of the sample region during a predefined interval;
• and
• computer usable program code for comparing the performance in the primary region to the performance in the sample region and adjusting the read/write area ratio of the primary region according to the comparison.

A cache system, comprising:

• a cache having a primary region that is split into a read portion and write portion and one or more sample region each split into a read portion and a write portion;
• counters for tracking hits in the primary region and hits in each of the one or more sample region during a predefined interval;
• a comparator for comparing a hit rate in the primary region to a hit rate in each of the one or more sample region;
• and
• a cache controller including control logic for caching reads and writes from a hard disk such that each cached read is located at the read portion of the sample region or primary region and each cached write is located at the write portion of the sample region or primary region, and for adjusting the read/write area ratio of the primary region according to the comparison performed by the comparator.