Computer system including a device with a plurality of identifiers

• US 20010044863A1
• Filed: 04/05/2001
• Published: 11/22/2001
• Est. Priority Date: 03/16/1992
• Status: Active Grant

• Current Assignee: Kiyoshi Honda, Minoru Yoshida, Naoto Matsunami, Takashi Oeda
• Original Assignee: Kiyoshi Honda, Minoru Yoshida, Naoto Matsunami, Takashi Oeda
• Inventors: Oeda, Takashi, Yoshida, Minoru, Honda, Kiyoshi, Matsunami, Naoto
• Granted Patent: US 6,499,075 B2
• Time in Patent Office: Days
• US Class Current: 710/104
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A host computer is connected with a magnetic disk storage device by a SCSI bus. In the magnetic disk storage device, a plurality of partitions are set in a disk drive unit and have device identifiers (ID'"'"'s) respectively allocated thereto as SCSI ID'"'"'s=1, 2 and 3, which are supported by a disk controller. When the host computer has acquired the control of the SCSI bus through an arbitration and has selected, for example, the partition with the device identifier SCSI ID=1, the disk controller permits the host computer to access the partition in response to the selection. Since the partitions are different in attributes, properties etc., they seem to be magnetic disk storage devices that at separate from one another when viewed from the host computer. Thus, the single magnetic disk storage device can be managed as a plurality of storage devices of different nature.

Claims

1. A computer system having a computer and a peripheral device, wherein peculiar device ID'"'"'s (identifiers) are respectively allocated to the computer and the peripheral device, and wherein data are transferred between the computer and the peripheral device by the use of the device ID'"'"'s;

said peripheral device comprising;

division means for dividing a function of said peripheral device itself into a plurality of sub functions;

means for affording a plurality of device ID'"'"'s to the respective sub functions obtained with said division means;

means for comparing the device ID designated by said computer, with the plurality of afforded device ID'"'"'s; and

means for executing the sub function which corresponds to the device ID having coincided as a result of the comparisons.

2. A computer system as defined in

claim 1

, wherein said peripheral device is an external storage device, said division means divides said external storage device into a plurality of partitions, and said computer accesses said plurality of partitions as if they were separate peripheral devices, by the use of said plurality of device ID'"'"'s afforded to said external storage device.

3. A computer system as defined in

claim 2

, wherein the respective partitions are endowed with different attributes.

4. A computer system wherein first and second computers and a peripheral device are connected through a common bus, and wherein the first and second computers access the peripheral device;

comprising;

means for allocating peculiar device ID'"'"'s to the first computer and the second computer, respectively; and

means for allocating a plurality of device ID'"'"'s to said peripheral device;

a specified one of said plurality of device ID'"'"'s of said peripheral device being used for only the access by said first computer;

another of said plurality of device ID'"'"'s of said peripheral device being used for only the access by said second computer.

5. A computer system having first and second computers, and a peripheral device which is connected to only the second computer;

comprising;

means for allocating peculiar device ID'"'"'s to the first computer and said peripheral device, respectively; and

means for allocating to said second computer a device ID which is peculiar to said second computer, along with the same device ID as the device ID allocated to said peripheral device;

said first computer including means for issuing a command to said second computer by designating the allocated device ID of said peripheral device in order to access said peripheral device;

said second computer including means for accessing said peripheral device upon receiving said command, and for sending a result of the access to said first computer.

6. A computer system as defined in

claim 5

, wherein said peripheral device is an external storage device which is divided into a plurality of partitions, and different device ID'"'"'s are allocated to the respective partitions.

7. A computer system having a plurality of computers which include first and second computers of different communication protocols, and a peripheral device for the plurality of computers;

comprising;

means for allocating peculiar device ID'"'"'s to said first and second computers, respectively; and

means for dividing a function of said peripheral device into a plurality of sub functions corresponding to a plurality of communication protocols, and for allocating peculiar device ID'"'"'s to the respective ones of said plurality of sub functions;

said first and second computers accessing said peripheral device by the use of said device ID'"'"'s corresponding to said communication protocols of their own, respectively.

8. A computer system as defined in

claim 7

, wherein one of said first and second computers can select both of said different communication protocols.

9. A computer system as defined in

claim 8

, wherein said peripheral device is an external storage device which is divided into a plurality of partitions, and different device ID'"'"'s are allocated to the respective partitions.

10. An external storage device which is accessed from a computer by designating a device ID of the external storage device;

comprising;

division means for dividing said external storage device itself into a plurality of partitions;

memory means for storing peculiar device ID'"'"'s for the respective partitions obtained with said divisions means;

comparison means for comparing said device ID designated by said computer, with the plurality of device ID'"'"'s stored in said memory means; and

control means for accessing the partition which corresponds to the device ID having coincided as a result of the comparisons by said comparison means, and for sending a result of the access back to said computer.

11. An external storage device as defined in

claim 10

, wherein said plurality of partitions are respectively endowed with different attributes.