Back to results
US 5,862,363 AGranted
Method of controlling a disk device by disk control unit
AssigneeFujitsu Limited
InventorsYuichi Taroda, Keishichiro Tanaka, Kazuma Takatsu
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeFujitsu Limited
InventorsYuichi Taroda, Keishichiro Tanaka, Kazuma Takatsu
Estimating the term…
One CKD track on a direct-access storage device is divided into a plurality of fixed-length FBA blocks, only a home address HA of the CKD track and a record R0 having a CKD format are recorded in the leading FBA block, and each field (a COUNT field, KEY field and DATA field) of records R1, R2, . . . having the CKD format is recorded in the other FBA blocks. This arrangement is such that even if a format-write processing instruction for format-write from the record R1 is received from a host device, a disk control unit will not read the FBA block of HA/R0 out to a cache memory and will read out only FBA blocks from record R1 onward. As a consequence, write processing from record R1 onward can be performed in memory with ease and format-write processing can be executed at high speed.
A method of controlling a disk device by a disk control unit provided between a host device, which issues input/output instructions in a variable length recording format (a CKD format), and a disk device having a recording format of a fixed length (an FBA format), for performing an emulation between the CKD format and the FBA format in a memory and accessing the disk device in fixed-length units, comprising steps of:
A disk control unit provided between a host device which issues input/output instructions in a variable length recording format(a CKD format), and a disk device having a recording format of a fixed length (an FBA format), for performing an emulation between the CKD format and the FBA format in memory and accessing the disk device in fixed-length units, comprising steps of:
Dependencies are inferred from the claim text.