Hard disk drive with attached solid state drive cache

A method for managing computer storage, the method comprising:

• making a determination whether data corresponding to a read request is available in a solid state drive (SSD) memory when the read request causes a miss in a memory cache;
• serving the read request from the SSD memory when the determination is that the data is available in the SSD memory;
• and
• invoking SSD memory tracking logic and serving the read request from a hard disk drive (HDD) when the determination is that the data is not available in the SSD memory, the invoking further including:
• allocating a new tracking element for the data corresponding to the read request when the data is not being tracked by the SSD memory tracking logic;
• and
• marking a page associated with the data for asynchronous background fetching into the SSD memory when a fetch criteria has been met, wherein the SSD memory tracking logic loads the data in the SSD memory when the data corresponds to random memory reads, wherein the SSD memory acts as a memory read cache, wherein the SSD memory does not act as a write memory cache.

A system for managing computer storage, the system comprising:

• a cache manager;
• HDD storage;
• a RAM cache;
• and
• an SSD cache, the RAM cache and the SSD cache storing HDD storage data;
• wherein the cache manager determines whether data corresponding to a read request is available in the SSD cache when the read request causes a miss in the RAM cache;
• wherein the read request is served from the SSD memory when the data is available in the SSD memory;
• wherein SSD memory tracking logic is invoked and the read request is served from the HDD storage when the data is not available in the SSD cache, wherein invoking the memory tracking logic further includes:
• allocating a new tracking element for the data corresponding to the read request when the data is not being tracked by the SSD memory tracking logic;
• and
• marking a page associated with the data for asynchronous background fetching into the SSD memory when a fetch criteria has been met, wherein the SSD memory tracking logic determines whether a fetch criteria for the data has been met, and the SSD memory tracking logic loads the data corresponding to the read request in the SSD memory when the fetch criteria has been met;
• wherein the SSD memory performs as a read cache for the HDD storage, and the SSD memory does not perform as a write cache for the HDD storage.

A computer program embedded in a non-transitory computer-readable storage medium, when executed by one or more processors, for managing computer storage, the computer program comprising:

• program instructions for making a determination whether data corresponding to a read request is available in a solid state drive (SSD) memory when the read request causes a miss in a memory cache;
• program instructions for serving the read request from the SSD memory when the determination is that the data is available in the SSD memory;
• and
• program instructions for invoking SSD memory tracking logic and serving the read request from a hard disk drive (HDD) when the determination is that the data is not available in the SSD memory, the invoking further including:
• program instructions for allocating a new tracking element for the data corresponding to the read request when the data is not being tracked by the SSD memory tracking logic;
• and
• program instructions for marking a page associated with the data for asynchronous background fetching into the SSD memory when a fetch criteria has been met, the SSD memory tracking logic loading requested data in the SSD memory when the requested data corresponds to random memory reads, wherein the SSD memory has a section that performs as a permanent storage drive containing data which is not in the HDD and a section that performs as a random read cache for the HDD.