International Business Machines Corporation

Mario Yamaguchi

Spencer W Ng

Richard K Treiber

Jonathan Mark Haswell

Tatsuya Sakai

Minoru Hashimoto

Jon Haswell

When writing user data D, the user data D is stored in a register 46, and using both the user data D and the sector information (ID) of the user data D, an error correction code ECC is generated by an ECC generation algorithm Ar. A stored information Rw made up of the user data D and the generated ECC is written on a disk. In the reading, the user data Dr of a read record Rr is temporarily stored in the register 46, and an ECC check algorithm is executed. This ECC check is executed for combined data of the user data Dr and its position information. When any error is found in the position information portion in the combined data, the user data is determined that the read user data is wrongly addressed. When an error is found in the user data Dr portion, the user data is corrected by ECC and the corrected user data is output.

Data processing method and data storage system

A system manages data transfer between a computer, a data storage disk, and a data buffer which is associated with the disk. Upon receipt of a write request during data read-ahead from the disk to the buffer, the system preempts the read-ahead to write the data to the disk only when the target write track on the disk is different from the track being read ahead into the buffer. Otherwise, the system permits read-ahead to continue until the target write sector is positioned beneath the disk drive head. Also, upon receipt of a read request during cache writing from the buffer to the disk, the system immediately satisfies the read request prior to completing the cache writing when the requested read data is contained in the buffer. Moreover, the system provides for dynamic switching between a data read-ahead preempt policy and a data read-ahead no-preempt policy based upon parallel monitoring and comparison of data request service times under both policies.

Method and apparatus for computer disk drive buffer management

Method and apparatus for computer disk drive management

Growing community of inventors

Yokohama, Japan

Mario Yamaguchi