Kabushiki Kaisha Toshiba

Ikuko Iida

Yasuhiko Ichikawa

A hang-up detector and an interrupt generator are provided in a disk controller incorporated in a disk storage system. By monitoring a command execution period, the detector detects whether the disk storage system reaches a hang-up state during the execution of a command in the system. The interrupt generator generates an interrupt to a CPU when the detector has detected the hang-up state. Upon receiving the interrupt, the CPU executes control for re-executing the command.

Disk controller for detecting hang-up of disk storage system

A CPU increments the variation in the corresponding monitor value in a monitor value storage area secured in a RAM, each time an event to be monitored has occurred. When the monitor value must be stored, the CPU adds the incremented one of the variations in the individual monitor values stored in the monitor value storage area to the corresponding value in a monitor value saving area secured in the system area of the disk, executes monitor value saving control by which the monitor value is replaced with the resulting monitor value, and then clears the monitor value storage area.

Disk drive with a PFA function and monitor value saving control method

A buffer memory is prepared to temporarily store data sequentially read out from consecutive storage positions of a magnetic disk. When a read request is received from a host system, and an HDC reads out the requested data from the magnetic disk, the readout data is written in a buffer area in the buffer memory, which is assigned by a CPU and designated by a buffer management data portion, from the start position to the end position of the area. If the requested data exceeds the capacity of this area, the start address returns to a position indicated by a new start buffer address set in the buffer management data portion which is set by the CPU, e.g., a middle point in the buffer area, and the succeeding readout data is stored in the buffer area from the middle point to the end position. The requested data stored in the buffer memory is sequentially transferred to the host system. In the area extending from the start address, set in the buffer management data portion, to the end position, an area from which data is transferred to the host system is recognized as a free area, and succeeding data is sequentially stored therein by the HDC.

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Tokyo, Japan

Ikuko Iida