PURPOSE: To effectively control a duplex disk device.
CONSTITUTION: A duplex disk constitution 2 is formed when the same data are written in two disk devices 3 and 4, and the data are written into and read out of the constitution 2 by a channel device 1. This device 1 is provided with a storage means 6 which stores the commands which are sent to the devices 3 and 4 for each constitution 2 and a control means 5 which selects a means 6 for each constitution 2 to store the commands and also sends the stored commands to both devices 3 and 4 constructing a constitution 2. In such a constitution, the first command is read out of the means 6 and sent to the devices 3 and 4 respectively. When the commands are chained together, the first command is sent to one of both disk devices that is first through with its operation of the first command and then the next command is sent to the other disk device that is through later with the first command.
TAKAHASHI KIYOSHI
YAMAMOTO SHIGEHARU
