Maximizing sequential read streams while minimizing the impact on cache and other applications

A method for controlling transfers of records in a record storage system between storage devices, a cache and a host computer, said method comprising the steps of:

• initiating a prefetch of a number of records from the storage devices for transfer to the cache in order to return requested records to the host computer in response to a read request from the host computer;
• detecting if a previous prefetch is complete;
• if the prefetch is not complete, increasing the number of records in a next prefetch of records by a preset amount and initiating the next prefetch of records;
• if the prefetch is complete, initiating a next prefetch of records with the number of records in the prefetch being the same as in the previous prefetch;
• returning requested records from the cache to the host computer in response to the read request when the requested records are available from the cache;
• and
• releasing storage space in the cache of each requested record after the requested record has been returned to the host computer.

A dynamic cache management method for controlling a size of a prefetch of records from a storage device to a cache, comprising:

• receiving a read request from a host computer for a number of the records in the storage device;
• determining if the read request is for sequential ones of the records in the storage device;
• detecting whether the requested records are in the cache to identify a cache hit or miss;
• when the read request is identified as a cache miss, setting the initial size of the prefetch to the number of the requested records in the read request;
• and
• if determined sequential, initiating the prefetch with the set size.