JPH06139178A - Device for extending storage device - Google Patents

Abstract

PURPOSE:To increase the storage capacity of a system without adding machine numbers and changing the system. CONSTITUTION:This storage device extending device 3 capable of connecting a host device 1 and plural storage devices to be accessed by the host device 1 based upon machine number specification and address specification includes a converter 5 for storing conversion informaltion allowing areas specified by the machine numbers and addresses of storage devices 4-1 to 4-n extended on the same level as that of a reference storage device 2 to correspond to addresses continued to the machine number of the device 2 at the rate of 1 to 1 and a control device 6 allowing the host device 1 to access the areas of all the storage devices 4-1 to 4-n as the machine number area of the reference storage device 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage device expansion device, and more particularly to a storage device expansion device in a device to which a host device and a plurality of storage devices accessed by the host device by designating a machine number and an address can be connected. Regarding the device.

[0002]

2. Description of the Related Art SCSI (small co) is used as an interface for connecting a host device and a magnetic disk device.
There is a so-called mputter system interface). Currently, SCSI is a standard for ensuring its versatility, and the number of terminal devices such as storage devices that can be connected to a host device is limited.

That is, as shown in FIG. 4, for example, seven magnetic disk devices 21 to 2 as storage devices are under the control of a host controller 20 (referred to as an initiator).
Only 7 can be connected. Here, a SCSI controller 211 is provided in the magnetic disk device, and the drive of the drive device 212 is controlled by the access of the host controller 20. This access is performed by designating the machine number (1 to 7) of the magnetic disk device and the address in the device. For example, the XX address of the first machine number is designated.

[0004]

By the way, when it is desired to increase the storage capacity of the entire conventional system, the capacity of the magnetic disk device itself is limited because the number of installed SCSI devices with a drive device is limited. In addition to increasing the number, a method as shown in FIG. 5 is adopted. This is to connect a plurality of drive devices 41 to 4n under the control device 311 of a specific magnetic disk device 31 when seven magnetic disk devices 31 to 37 are already connected to the host controller 30. is there. As a result, the storage capacity can be increased.

However, when the drive device is added by such a method, the access from the host control device is different from the conventional one. That is, in order to distinguish between the drive device 312 originally existing in the magnetic disk device 31 and the added drive devices 41 to 4n, the drive 312 has the machine number 1-0 and the drive device 41 has the machine number 1-.
In the same way as 1 and below, a machine number different from the conventional one will be introduced.

As described above, there is a demand for avoiding the addition of the machine number (address) or the change of the system configuration accompanying the addition of the drive machine number as much as possible. Therefore, an object of the present invention is to provide a storage device expansion device capable of increasing the storage capacity of the system without adding a machine number or changing the system.

[0007]

In the present invention, the means for solving the above-mentioned problems is, as shown in FIG. 1, a host device 1 and this host device 1 which are accessed by designating a machine number and an address. A storage device expansion device 3 in a device to which a plurality of storage devices can be connected, and is specified by the machine numbers and addresses of the storage devices 4-1 to 4-n which are expanded on the same side as the basic storage device 2. A conversion device 5 for storing conversion information for making the area to correspond to a continuing address in the machine number of the basic storage device 2 one-to-one;
Based on the conversion information of 1., a control device 6 that causes the host device to access all storage device areas as the machine number area of the basic storage device.

In the first means, the control device 6 may have a switching means 7 which allows the host device 1 to access only the basic storage device 2.

[0009]

According to the first means of the present invention, the conversion device 5 has the storage device 4-1 which is added on the same side as the basic storage device 2.
The area specified by the 4-n machine number and address is set to 1 for the continuing address in the machine number of the basic storage device 2.
It stores conversion information corresponding to one-to-one.

Then, the control device 6 causes the host device to access the areas of all the storage devices as the machine number area of the basic storage device based on the conversion information of the conversion device 5, so that the storage capacity is reduced. Even if it increases, it does not change the machine number or system. The second aspect of the present invention
According to this means, only the basic storage device can be targeted for access by the switching means, if necessary.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an embodiment of a storage device expansion device according to the present invention. In the present embodiment, a magnetic disk device 12 including a storage device expansion control device 13 is connected to the host controller 11 via SCSI. The magnetic disk device 12 includes a basic drive device 121 (drive 1) in addition to the storage device expansion device, and is connected to two expansion drive devices 141 and 142 (drive 2 and drive 3).

Further, the storage device expansion device 13 has a microprocessor 16 (MPU) which is a control device, a drive pair address table 15 which is a conversion device, and a switch 17 (SW) which is a switching means. The drive-to-address table 15 stores the addresses of the drives 1 to 3, for example, each address has addresses 0 to 99. When a drive is added, the switch 17 is set so as to increase the capacity of the added drive as a basic drive. Then MPU16
(Microprocessor) recognizes the setting condition,
When the access command is issued from the upper control unit, the access position is converted by the drive-to-address table and the storage area of the drive is designated. That is, the additional drive is shown as the same model number as the basic drive as if the storage capacity of the basic drive is increased. That is, it can be seen from the host device that the machine number 1 has addresses 0 to 299.

The MPU 16 notifies the host device that there is a machine number area having a capacity of three drives and the host apparatus specifies the address of machine number 1 to access the area. Then, the MPU 16 accesses the drive 1 from the 0th address to the 99th address and the 19th address from the 100th address.
Access to address 9 is to drive 2, and access from address 200 to 299 is to drive 3.

Here, when the switch 17 is switched, MP
U16 is supposed to notify the host device that the machine number 1 has the capacity of one drive, that is, the addresses 0 to 99 exist. Next, a processing procedure of the storage device adding apparatus according to the present embodiment will be described based on the flowchart shown in FIG.

First, the host controller recognizes the configuration of SCSI and the drive under the SCSI by a command (S
1). It is determined whether there is one connected drive or a plurality of connected drives, and the respective processes are performed. In this case, one drive means the case of the above-mentioned embodiment, and there is no other drive, and a plurality of drives means the configuration as shown in FIG. 4 as a conventional example. If you have.

If there is only one drive, the host controller issues a READ CAPACITY command to check the capacity of the drive (S3). Then, the control unit (storage device expansion device) of the basic drive notifies the host controller of the total capacity of the connected drive devices (drives 1 to 3 in the above embodiment) (S4). The host controller issues a read / write command for the area of the designated address (S6), and the MPU of the storage device expansion device designates the address from the host controller by the drive pair address table and the drive device and its address. , Issue read / write command. As a result, each drive executes the read / write processing of the address area it is in charge of (S7).
Thereafter, the processes of S5 to S7 are executed as needed.

On the other hand, when there are a plurality of connected drives, the host controller issues a READ CAPACITY command to check the capacity of the drives (S8). Then, the control unit of the basic drive notifies the upper control unit of the capacities of the drive devices (the drives 1 to 7 in the conventional example) connected to the upper control unit (S9). The host controller issues a read / write command for the area of the address of the designated drive (S10), whereby each drive executes the read / write processing of the address area it is in charge of (S10).
11). Thereafter, the processes of S10 to S11 are executed as necessary.

Therefore, according to the present embodiment, even if the storage capacity is increased by adding a drive device, there is no change in the machine number or the system, and the user can automatically connect the additional drive. Capacity can be increased. Further, if necessary, only the basic storage device can be accessed by operating the switch. Further, according to the present embodiment, when accessing the storage devices having the same capacity, the capacity of one drive device can be reduced, so that the processing time can be shortened.

[0019]

As described above, according to the present invention,
One-to-one correspondence between the area specified by the machine number and the address of the storage apparatus that has been added on the same side as the basic storage apparatus in the expansion apparatus of the storage apparatus, and the continuing address in the machine number of the basic storage apparatus. A conversion device that stores conversion information to be provided, and a control device that allows the host device to access all storage device areas as the basic storage device number area based on the conversion information of the conversion device Therefore, it is possible to increase the storage capacity automatically by connecting an additional drive without changing the system drive configuration. Also, by seeing multiple drives as one drive, the drive by table reference can be used. Since the selection is made, there is an effect that the drive can be distributed and the processing time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing the principle of the present invention.

FIG. 2 is a block diagram showing an embodiment of a storage device adding device according to the present invention.

FIG. 3 is a flowchart illustrating a processing procedure of the storage device expansion device according to the embodiment.

FIG. 4 is a block diagram showing an example of a conventional technique.

FIG. 5 is a block diagram showing another example of the conventional technique.

[Explanation of symbols]

 1 host device 2 basic storage device 3 storage device expansion device 4 expanded storage device 5 conversion device 6 control device 7 switching means

Claims (2)

[Claims] 1. A host device (1) and a storage device expansion device (3) in a device to which a plurality of storage devices can be connected by which the host device (1) accesses by designating a machine number and an address, Continuation of the area specified by the machine number and address of the storage devices (4-1 to 4-n) that are added on the same side as the basic storage device (2) in the model number of the basic storage device (2). A conversion device (5) that stores conversion information that makes one-to-one correspondence with an address to be stored, and a storage device that is based on the conversion information of the conversion device (5) and that is based on all storage device areas for the host device. And a control device (6) which is accessed as the machine number area of the storage device expansion device. 2. The control device (6) has a switching means (7) for allowing the host device (1) to access only a basic storage device (2). Item 1. A storage device expansion device according to item 1.