초록 ▼

In a cache/disk sybsystem employing the post-store technique, each file is assigned a file number. The file number is an address in a directory on a disk, this address containing pointers to the physical disk space assigned to that file. During normal operation of the subsystem a device number and a

In a cache/disk sybsystem employing the post-store technique, each file is assigned a file number. The file number is an address in a directory on a disk, this address containing pointers to the physical disk space assigned to that file. During normal operation of the subsystem a device number and address are utilized to transfer written-to segments of data from a cache store to a disk. If a failure occurs which prevents the cache-to-disk transfer of a segment of data, a storage control unit forms a status word and a sense message. The sense message includes the file number and information defining the fault. A host processor is then notified that the status word is available. The host processor obtains the status word and indexes into a status action branch table. The branch table entry directs the host processor to issue a Sense I/O command to obtain from the storage control unit the sense message identifying the fault. The executive program of the host processor may subsequently utilize the sense message, which also includes the file number, to assign new disk space at which the segment of data may be recorded. The segment of data which could not be written to the disk is first read into the host processor. The host processor then issues a command to write the segment of data into the newly assigned disk space.

대표청구항 ▼

In a cache/disk system including a host processor for issuing commands specifying an operation to be performed and an address, a disk drive device for driving a disk, a cache store for storing segments of data, a segment descriptor store for storing a segment descriptor corresponding to each of said

In a cache/disk system including a host processor for issuing commands specifying an operation to be performed and an address, a disk drive device for driving a disk, a cache store for storing segments of data, a segment descriptor store for storing a segment descriptor corresponding to each of said segments of data, and a storage control unit interfacing with said host processor, said disk drive device, said cache store and said segment descriptor store, said storage control unit including means for destaging to said disk segments of data which have been written to while in said cache store, the improvement comprising: means in said host processor for issuing a file number as part of a command, said file number specifying an address in a directory recorded on said disk; means in said storage control unit for storing said file number as part of the segment descriptor associated with a data segment involved in the operation specified by the command; detecting means for detecting when said means for destaging segments of data to said disk is unable to destage a segment; means responsive to said detecting means for generating a status word and a sense message, said sense message including said file number; means for transmitting said status word and said sense message to said host processor; means in said host processor responsive to said sense message for reading into the host processor the segment of data which could not be destaged and for assigning new disk space to store the segment of data which could not be destaged; and means in said storage control unit responsive to a command from the host processor for writing into the new disk space that segment of data which could not be destaged.