| 摘要 |
PURPOSE:To access quickly data existing in a mass storage, by allowing a virtual computer to prestage a data on the mass storage into a mass storage device on a basis of the private operating control. CONSTITUTION:When a virtual computer B12 uses a virtual volume, the computer B12 issues a mount request to a control program OS operated on the computer B12. The mount request is converted to a mount order to a mass storage controller 13 by the OS and is issued as an I/O request. When receiving the mount order, the controller 13 stages only the region of a requested cylinder to a mass storage device DASD 17 controlled by a staging controller SDC 14. Though a mass storage facility MSF 16 moves a cartridge to a data recording mechanism each time the stage processing is performed, the OS prestages the region, which is judged to be necessary, on the mount-requested virtual volume. Thus, the access time is shortened. |
