초록 ▼

Data transfers between respective buffer segments and data source-sinks, such as peripheral data storage devices, are scheduled as a series of transfers based upon most recent, next most recent, to the least recent usage of the buffer segments by a utilization device. A list of segments ordered by s

Data transfers between respective buffer segments and data source-sinks, such as peripheral data storage devices, are scheduled as a series of transfers based upon most recent, next most recent, to the least recent usage of the buffer segments by a utilization device. A list of segments ordered by such usage is dynamically maintained. Replacement of segment allocations among devices proceeds from the least recently used, next least recently used, etc. to the most recently used segments. Therefore a single list controls replacement and read ahead (prefetch) of data from devices to the buffer and transfer of data from the buffer to the devices, all based on utilization of the buffer by the utilization device.

대표청구항 ▼

The machine-implemented method of operating a storage subsystem having a data buffer with a plurality of buffer data storage spaces and being connected to and shared by a plurality of data storage devices, such buffer data storage spaces being selectively allocatable to said devices; the method incl

The machine-implemented method of operating a storage subsystem having a data buffer with a plurality of buffer data storage spaces and being connected to and shared by a plurality of data storage devices, such buffer data storage spaces being selectively allocatable to said devices; the method including the automatic machine-implemented steps of: allocating certain ones of said buffer data storage spaces to respective predetermined ones of said data storage devices for effecting data transfers between said certain ones of said data storage spaces of said buffer and said respective predetermined ones of said devices; accessing said buffer independently of said devices, maintaining a single list of all said certain ones of said buffer storage spaces based upon said independent accesses from a most recent access through more recent accesses and less recent accesses to a least recent access; transferring data between respective ones of said allocated certain ones of said buffer data storage spaces and said predetermined ones of said data storage devices in a predetermined sequence of data transfers beginning with said most recent, then said more recent, said less recent and finally said least recent accessed ones of said allocated buffer data storage spaces identified in said maintained list; and reallocating said buffer data storage spaces between said predetermined ones of said data storage devices to other ones of said data storage devices beginning with said least recently used and continuing with said less recently used ones of said buffer storage spaces.