Computer system including a device with a plurality of identifiers

• US 5,634,111 A
• Filed: 03/16/1993
• Issued: 05/27/1997
• Est. Priority Date: 03/16/1992
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Oeda, Takashi, Yoshida, Minoru, Honda, Kiyoshi, Matsunami, Naoto
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Myers, Paul R.
• Application Number:
  US08/031,880
• Time in Patent Office: 1,533 Days
• Field of Search: 395/325, 395/650, 395/405, 395/480, 395/497.04, 364/246.3
• US Class Current: 711/153
• 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 an 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 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 appear as magnetic disk storage devices that are 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 comprising:

a plurality of computers; and

an external storage device which is connected to said plurality of computers via a common bus, wherein each of said plurality of computers includes means for transferring device ID'"'"'s and commands to said external storage device

wherein said external storage device comprises;

division means for dividing a storage area of the external storage device into a plurality of partitions,

means for affording a plurality of respective device ID'"'"'s to each of said divided partitions,

means for selecting a partition which has been afforded a device ID corresponding to the device ID transferred from said computers, and

means for controlling access to said selected partition in accordance with a command transferred together with the device ID and for transferring a result of the access to said computers,

wherein each of the device IDs transferred to said external storage device from each of said computers differ from each other.

2. A computer system as defined in claim 1, wherein said respective divided partitions are endowed with different attributes.

3. An external storage device as defined in claim 1, wherein said plurality of partitions are respectively endowed with different attributes.

4. A computer system as claimed in claim 1, wherein said means for selecting a partition comprises:

a plurality of registers where the device ID'"'"'s, which have been afforded to each of said divided partitions, are stored; and

a circuit for comparing the device ID'"'"'s stored in a plurality of said registers, respectively with the device ID'"'"'s transferred from said computers.

5. A computer system comprising:

first and second computers being connected to each other; and

an external storage device which is connected only to said second computer, wherein each of said first and second computers includes means for transferring device ID'"'"'s and commands;

wherein said external storage device comprises;

division means for dividing a storage area of the external storage device into a plurality of partitions,

means for affording different device ID'"'"'s to each of said divided partitions,

means for selecting a partition which has been afforded a device ID corresponding to the device ID transferred from said second computer, and

means for controlling access to said selected partition in accordance with a command transferred together with the device ID and for transferring a result of the access to said second computer;

wherein further said second computer includes means for accessing said external storage device using a device ID and a command which have been transferred, when the device ID transferred from said first computer is the device ID allocated to said external storage device, and

wherein further, each of the device ID'"'"'s transferred to said external storage device from each of said plurality of computers differ from each other.

6. A computer system comprising:

a plurality of computers including a first computer having at least one communication protocol, a second computer; and

an external storage device,

wherein each of said first and second computers comprises means for transferring a device ID allocated corresponding to a communication protocol owned by each of said first and second computers;

wherein said external storage device comprises;

division means for dividing a storage area of said external storage device into a plurality of partitions,

means for affording different device ID'"'"'s to each of said partitions which have been divided,

means for selecting a partition which has been afforded a device ID corresponding to the device ID transferred from said computers, and

means for controlling access to said selected partition in accordance with a command transferred together with the device ID and for transferring a result of the access to said computers; and

wherein each of the device ID'"'"'s transferred to said external storage device from each of said plurality of computers differ from each other.

7. An external storage device which performs accessing in accordance with a device ID and a command transferred from a plurality of computers, said external storage device comprising:

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

means for affording different device ID'"'"'s to each of said partitions which have been divided;

means for selecting a partition which has been afforded a device ID corresponding to the device ID transferred from said computers; and

means for accessing said selected partition in accordance with a command transferred together with the device ID and for transferring a result of the access to said computers;

wherein each of the device ID'"'"'s transferred to said external storage device from each of said plurality of computers differ from each other.

8. A disk array storage device, comprising:

a disk array; and

a disk array controller for accessing said disk array in accordance with a SCSI-ID and a command transferred from a computer;

wherein said disk controller comprises;

division means for dividing a storage area of said disk array into partitions in accordance with a data management method,

means for affording different SCSI-ID'"'"'s to each of a plurality of said partitions of said disk array,

means for selecting a partition which as been afforded a SCSI-ID corresponding to the SCSI-ID transferred from said computer, and

means for controlling access to said selected partition in accordance with the data management method of the partition and a command transferred from said computer and for transferring a result of the access to said computer.