JPH05334006A - Logical volume system - Google Patents

Abstract

PURPOSE:To effectively use an idle disk space on a network by each computer device. CONSTITUTION:With respect to the logical volume which manages physical disks 101c, 102c, 102d, etc., provided in computer devices 101 to 103 connected through a network bus 100 as logical disks, the object of a physical volume in the logical volume is extended from physical disks in the same computer system to, for example, physical disks of another system through the network bus 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system, and more particularly to a logical volume system for managing a storage space of an actual disk device as a virtual logical volume.

[0002]

2. Description of the Related Art Systems in which a plurality of computer devices are connected to a network bus are used in various fields.

In such a system, each computer device generally includes one or more disk devices. However, in each computer device, the usage rate of the storage space in each disk device usually varies, and some computer devices lack storage space and some computer devices have excess storage space.

Therefore, it is conceivable that each disk unit is shared by a plurality of computers in order to make effective use of the device resources by taking advantage of the fact that the computers are networked together, which is realized in the conventional system. There are things that have been done.

By the way, as a means for simplifying control of a plurality of disk devices, a so-called "logical volume" virtual storage space is conventionally known. This logical volume is generally a virtual storage space that combines the storage spaces of a plurality of actual disk devices (physical volumes), and corresponds to a virtual large disk device. That is, only the logical volume can be seen from the basic system of the computer, and the complexity of directly controlling the individual disk devices by the basic system is eliminated.

Conventionally, examples of such logical volume adaptation include a disk striping method in which disks are divided and used for speeding up, a disk array method or disks in which disks are used in parallel to obtain a wider continuous area. A mirror disk method and the like have been proposed in which disks are multiplexed in order to cope with file damage due to a failure.

Further, regarding the logical volume, Japanese Patent Laid-Open No.
-10250 (Reference 1) and Japanese Patent Laid-Open No. 3-92942.
Examples thereof include those disclosed in Japanese Patent Publication (Reference 2) and the like. Here, in Document 1, at the time of creating a file, the physical volumes forming the corresponding logical volume are selected substantially evenly, and the files are distributed to the respective physical volumes, so that the access distribution of the physical volumes corresponding to the logical volumes is performed. We are working to improve access efficiency. Further, in Reference 2, files are stored and multiplexed in a disc in an arbitrary logical unit to improve the utilization efficiency of the disc.

[0008]

However, in the past, a logical volume via a network has not been constructed in a multi-computer environment. Therefore, the free space of the disk in the system cannot be effectively utilized freely.

Here, in the above-mentioned document 1, a plurality of disks in its own device managed by the OS are managed as logical volumes, and disks of other devices are not used.

Further, in Reference 2, although another disk is used via the network, since the control is performed at the level of the OS itself of the apparatus, a logical volume in which a plurality of disks are integrated and managed. Could not be used effectively. Therefore, for example, when the system in which the logical volume is constructed falls into an inoperable failure, there is a problem that all disks become inaccessible. In other words, OS level and disk I /
It was requested that a logical volume exist between it and the O level.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a logical volume system capable of effectively utilizing free disk space in a multi-computer environment.

[0012]

In order to achieve the above object, the present invention according to claim 1 provides an operating system section, at least one disk device, and a disk I / O management section for managing the disk device. , A network I / O management unit connected to a network bus, and a system in which a plurality of computer devices are connected to the network bus, in at least one computer device, the operating system unit and the disk I / O management unit. 1 in the system between the department
Alternatively, a logical volume management unit that integrally manages a storage space of a plurality of arbitrary disk devices as a logical volume that is a virtual storage space is provided, and the operating system unit uses the logical volume as a disk I / O management unit. A disk control command is issued on the assumption that they are equivalent, and the logical volume management unit determines the actual disk device corresponding to the disk control command from the operating system unit and controls the disk device. To do.

The invention according to claim 2 is characterized in that, in the above configuration, the logical volume management section and the network I / O management section are directly connected.

[0014]

According to the above configuration, the logical volume management unit is provided between the operating system unit and the disk I / O management unit, and the operating system unit performs control by regarding the logical volume as a disk owned by itself. .. That is, the logical volume is a combination of the storage spaces of the disk devices in the computer device and other computer devices, and the operating system unit does not care about the physical volume (disk device), and the virtual disk device. Disk control is performed for (logical volume).

In this case, the logical volume management unit determines which disk device is actually controlled by the operating system unit, and controls the disk device (write control or read control). .. If the control target is the disk device of the computer device, the disk device is connected via the disk I / O management unit to execute control. If it is another computer device, the network I of the computer device is connected. /
The disk device of the other computer device is connected through the O management unit and the network bus to execute control.

In the present invention, since a logical volume can exist between the operating system level and the I / O level, the burden on the operating system section is reduced and the complexity at the time of constructing the operating system section is reduced. it can.

[0017]

1 is a schematic block diagram of a hardware configuration showing a first embodiment of a logical volume system according to the present invention.

This system constitutes, for example, a LAN (Local Area Network), and a plurality of independent computer devices 101 and 102 are connected to a logical volume bus 100.

The computer device 101 includes a CPU 101a for controlling the operation of the entire device, a memory 101b such as a RAM, a disk control circuit 101d for the disk 101c, and a net interface circuit for interfacing with the network bus 100. 101e,
Are provided, and they are connected to the internal bus 101f.

Similarly, the computer device 102 has a C
PU 102a, memory 102b, disks 102c, 1
A disk control circuit 102e for 02d and a net interface circuit 102f are provided and connected to the internal bus 102g.

The operation of the system configured as described above is
This will be described with reference to FIGS. 2 and 3. 2 is a diagram showing a data flow during software operation of this embodiment, and FIG. 3 is a flow chart showing an execution flow of this embodiment. Further, 101 and 102 in FIG. 2 are the computer devices shown in FIG. 1, and 103 is another computer device.

In the client-side computer device 102 shown in FIG. 2, when a user issues a data write or data read command, the operating system (OS) causes the disk driver to start from the path (execution migration route between software) 201. Interface 20
2, the logical volume (DLVM) management unit 203
To disk control (read control, write control) (step S301). Here, the logical volume management unit 203 includes a virtual logical volume 203.
a is present. The logical volume management unit 203 determines which part of the logical volume 203a is the command target of the OS, and determines the disk device to be accessed and its position (step S302). Here, in the logical volume 203a, the computer device 1 is virtually
Data A stored in the disk device 101c of 01
Is included.

The logical volume management unit 203 has
A table for associating each address of the logical volume with the address in the actual storage space of each disk device is included. It also includes a control command decoding unit from the OS and a control command output unit to the disk device.

In this way, the logical volume management unit 203
Determines whether the device (disk device) to be accessed is remote, that is, another device on the network bus 100 (step S303). If the access target is its own disk device, the logical volume The management unit 203 controls the own disk device 102c or 102d as it is via the disk I / O driver (step S304), and ends this routine.

If the result of determination in step S303 is a disk device of another computer device, predetermined data is added to the control command in order to match the protocol in the network protocol unit 204, The generated signal is the network I / O driver 20.
The data is sent to the network bus 100 via 5 (step S305).

The signal transmitted to the network bus 100 is taken in by a remote server device (computer device 101 in this embodiment). That is, the computer device 101 is connected to the network bus 10
Receive said signal from 0 through network software. Specifically, the network I / O driver 2
Through 06, protocol processing is performed by the network protocol unit 207, the disk control command is extracted, and the disk process command is notified to the server process management unit 208 via the operating system (OS) (step S30).
6).

Upon receiving this, the server process management unit 208
Makes a disk I / O system call to the OS at path 209 in order to execute an I / O command for its own disk device (step S307). By this call, the OS sends the disk 1I / via the interface 210 and the logical volume management unit 211.
Issue a disk control (disk I / O) command to the O driver.

As a result, the disk device 101c is selected, and the disk device 1 is selected from the computer device 102.
Data reading of 01c is executed.

The logical volume does not necessarily have to exist in the computer device on the server side.

That is, according to the present invention, the OS level and I / O
A logical volume exists between the level and the disk, and the disk storage space on the network can be effectively utilized easily as viewed from the OS.

FIG. 4 is a diagram showing the configuration of the second embodiment, in which elements common to those in FIG. 2 are designated by the same reference numerals.

A logical volume 203 virtually existing in the logical volume management unit 103 of the computer device 102
Data b and data b are registered in b. Here, the data A is the same as the data A ′ and A ″ that are actually stored in the disk device 102c and the disk device 103a.
The data registered in 03b is the same as the data B'and B "actually stored in the disk devices 102d and 101c. That is, in this embodiment, the data is stored in duplicate. In this case, when the logical volume management unit 203 receives a read instruction of certain data, it normally selects one of the disk devices in which the same data is stored, but one disk device fails. If so, the so-called two data may be proofed to confirm the reliability of the data, if necessary.

FIG. 5 is a diagram showing the configuration of the third embodiment of the present invention, in which elements common to those in FIG. 2 are designated by the same reference numerals.

This embodiment is an example of a case where a larger single file is distributed and stored, and the logical volume 2
03c includes continuous data A-1, A-2, A-3.
Exists. Physical disks corresponding to this are the own disk device 102d and the other disk devices 103b, 1
03c, the disk 102d stores data A-1, and the disks 103b and 103c store data A-2 and A-3.

FIG. 6 is a diagram showing the configuration of the fourth embodiment of the present invention, in which elements common to those in FIG. 2 are designated by the same reference numerals.

This embodiment is an example in which high-speed data transfer is realized by the disk striping method, and data A to E exist in the divided area of the logical volume 203d. Physical disks corresponding to this are disks 101c and 103 in other computer apparatuses 101 and 103.
a, 103b, 103c, and data A, E on the disk 101c and data B, C, D on the disks 103a, 103b, 103c by the same operation as in the first embodiment. It is distributed and stored by the operation similar to the example.

[0037]

As described above, according to the present invention,
When there is free disk space on the network, the free storage space can be effectively used without complicating the structure of the operating unit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a hardware configuration of a network system having a logical volume according to the present invention.

FIG. 2 is a conceptual diagram showing the configuration and data flow of the first embodiment.

FIG. 3 is a flowchart showing an execution flow of the first embodiment.

FIG. 4 is a conceptual diagram showing the configuration and data flow of the second embodiment.

FIG. 5 is a conceptual diagram showing the configuration and data flow of the third embodiment.

FIG. 6 is a conceptual diagram showing the configuration and data flow of the fourth embodiment.

[Explanation of symbols]

100 network bus 101, 102, 103 computer device 203 logical volume management unit 101c, 102c, 102d, 103a, 103b,
103c Disk device 203a, 203b, 203c, 203d Logical volume

Claims (2)

[Claims] 1. A computer device including an operating system unit, at least one disk device, a disk I / O management unit for managing the disk device, and a network I / O management unit connected to a network bus. In a system connected to a plurality of the network buses, in at least one computer device, storage of one or more arbitrary disk devices in the system between the operating system unit and the disk I / O management unit A logical volume management unit that integrally manages the space as a logical volume that is a virtual storage space is provided, and the operating system unit regards the logical volume as a disk I / O management unit and issues a disk control command. The logical volume management unit A logical volume system characterized by determining an actual disk device corresponding to a disk control command from a plating system unit and controlling the disk device. 2. The logical volume system according to claim 1, wherein the logical volume management unit and the network I / O management unit are directly connected to each other.