Secondary cache for write accumulation and coalescing

A computer program product to efficiently destage data from a large secondary cache, the computer program product comprising a computer-usable medium having computer-usable program code embodied therein, the computer-usable program code comprising:

• computer-usable program code to accumulate, in a secondary cache, a plurality of data tracks, the data tracks comprising at least one of modified data and unmodified data;
• computer-usable program code to determine if a subset of the plurality of data tracks makes up a full stride;
• and
• computer-usable program code to destage the subset from the secondary cache in the event the subset makes up a full stride.

An apparatus to efficiently destage data from a large secondary cache, the apparatus comprising:

• a cache management module to accumulate, in a secondary cache, a plurality of data tracks, the data tracks comprising at least one of modified data and unmodified data;
• a determination module to determine if a subset of the plurality of data tracks makes up a full stride;
• and
• a destage module to destage the subset from the secondary cache in the event the subset makes up a full stride.

A caching system comprising:

• a primary cache to store data tracks comprising at least one of modified data and unmodified data;
• a secondary cache behind the primary cache;
• at least one disk drive behind the secondary cache;
• a cache management module to accumulate, in the primary cache, a plurality of data tracks, the data tracks comprising at least one of modified data and unmodified data;
• a determination module to determine if a subset of the plurality of data tracks makes up a full stride;
• and
• a destage module to destage the subset directly to the at least one disk drive in the event the subset makes up a full stride;
• and
• the destage module further configured to destage the subset to the secondary cache in the event the subset fails to make up a full stride.

A method comprising:

• accumulating, in a primary cache, a plurality of data tracks, the data tracks comprising at least one of modified data and unmodified data;
• determining if a subset of the plurality of data tracks makes up a full stride;
• and
• destaging the subset directly to at least one disk drive in the event the subset makes up a full stride;
• and
• destaging the subset to a secondary cache in the event the subset fails to make up a full stride.