Data access control system and computer-readable medium storing data access control program

A data access control system for transferring a plurality of data blocks to a plurality of storage units through a single data transmission channel, each within a scheduled time period, and sequentially writing the transferred data blocks into the plurality of storage units, the plurality of storage units being disposed on the single data transmission channel to allow the plurality of data blocks to be stored in a distributed manner, the data access control system comprising:

• vacancy monitoring means for finding a vacant time slot available in each of the storage units, the vacant time slot being a time period during which no data write operations are scheduled;
• and
• data write control means for finding a particular data block that is scheduled to be written into the storage unit of interest just before the vacant time slot detected by said slot vacancy monitoring means, and executing write retry operations during the vacant time slot if a write error is encountered when writing the particular data block.

A computer-readable medium encoded with a data access control program for sequentially reading out a plurality of data blocks from a plurality of storage units, and for transferring each data block through a single data transmission channel within a scheduled output time period, the plurality of storage units being disposed on the single data transmission channel to store the plurality of data blocks in a distributed manner, the data access control program being designed to run on a computer in order to cause the computer to function as:

• vacancy monitoring means for finding a vacant time slot available in each of the storage units, the vacant time slot being a time period during which no data read operations are scheduled;
• and
• data read control means for finding a particular data block that is scheduled to be read out just after the vacant time slot detected by said slot vacancy monitoring means has expired, prefetching the particular data block during the vacant time slot, and if a read error is encountered during the prefetch of the particular data block, conducting read retry operations until the scheduled output time period comes.

A computer-readable medium encoded with a data access control program for transferring a plurality of data blocks to a plurality of storage units through a single data transmission channel, each within a scheduled time period, and sequentially writing the transferred data blocks into the plurality of storage units, the plurality of storage units being disposed on the single data transmission channel to store the plurality of data blocks in a distributed manner, the data access control program being designed to run on a computer in order to cause the computer to function as:

• vacancy monitoring means for finding a vacant time slot available in each of the storage units, the vacant time slot being a time period during which no data write operations are scheduled;
• and
• data write control means for finding a particular data block that is scheduled to be written into the storage unit of interest just before the vacant time slot detected by said slot vacancy monitoring means, and executing write retry operations during the vacant time slot if a write error is encountered when writing the particular data block.