JPH08272685A - Computer system - Google Patents

Abstract

PURPOSE: To recognize an external storage device itself from the program operated on a system to access it in the computer system provided with a storage subsystem where external storage devices are managed as logical devices. CONSTITUTION: The system is provided with an external storage device constitution management part 11 which manages configuration information or external storage devices 4 connected to the system, an external storage device access management part 13 which generates such virtual devices based on this configuration information that a program 5 operated on the system can directly handle individual external storage devices 4 independently of management of the storage subsystem 3, an external storage device access part 14 which performs the issue processing or input/output requests to virtual devices, an external storage device exclusion part 16 which exclusively controls the use of common external devices 4 between virtual devices and logical devices at need, and an input/output request path exclusion part 18 which exclusively controls the issue of input/output requests to both or virtual and logical devices using different input/output paths.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to computer systems.

[0002]

2. Description of the Related Art An external storage device used by a computer system may be virtualized for the purpose of data integrity and expandability. As an example thereof, there is generally a method of dividing a storage area of an external storage device into a plurality of areas and selectively combining the respective divided areas to generate one or more virtual storage areas (hereinafter referred to as logical devices). .

In a computer system having a storage subsystem that is means for managing such logical devices, the programs that operate on the system are limited to those logical devices that can be recognized as storage devices. The actual external storage device itself cannot be recognized or directly accessed. Further, although there is a management area in the external storage device in which management information necessary for the storage subsystem to manage the logical device exists, this management area cannot be referenced from the program.

Such a restriction poses a problem when a program on the system cannot be performed without directly accessing the external storage device, for example, when the external storage device itself is tested immediately after disk replacement.

[0005]

In a conventional computer system having a storage subsystem which is a means for managing an external storage device as a logical device in this way, a program operating on the system is connected to an external device connected to the system. The storage device itself could not be recognized and accessed.

The present invention has been made in consideration of such circumstances, and in a computer system having means for managing an external storage device as a logical device, the external storage device itself is recognized from a program operating on this system. The purpose is to provide a computer system that can be accessed by accessing.

[0007]

In order to achieve the above-mentioned object, a computer system according to claim 1 of the present invention divides a storage area of each of a plurality of external storage devices into a plurality of areas and selects each of the divided areas. A computer system having a management means for generating and managing one or more logical devices by a physical combination, a configuration information generating means for generating physical configuration information of the individual external storage devices, and a configuration information generating means. Based on the generated physical configuration information of the external storage device, a program that operates on a computer system defines a virtual device that can directly handle each external storage device regardless of the management of the management unit. Virtual device generation means for generating, and a virtual device generated by the virtual device generation means in response to a request from the program Against it made by and a virtual device access means for issuing O requests.

According to a second aspect of the present invention, in the computer system according to the first aspect, when an external storage device is used as a component of the logical device under the control of the management means, the external storage device is present. The generation of the virtual device that accepts a write request to the external device is prohibited, and when an external storage device is used as the virtual device, the external storage device to the logical device that accepts a write request to the external storage device is accepted. It further comprises means for prohibiting incorporation.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the computer system described above, a plurality of input / output paths capable of transmitting a common input / output request to the external storage device, and a logical device input / output request monitor for monitoring generation of an input / output request from the management means to the logical device Means, a virtual device input / output request monitoring means for monitoring the generation of an input / output request for the virtual device, and each input / output request detected by the respective input / output request monitoring means for the common external storage device. If the input / output request is different from the input / output request, the input / output request set in advance is different from the input / output request set in the input / output request. It further comprises an input / output request exclusion means for controlling to issue the input / output request exclusively.

According to a fourth aspect of the present invention, in the computer system according to the third aspect, priority route setting means capable of arbitrarily setting a priority route among the plurality of input / output routes with respect to each individual input / output request. Priority route confirmation, wherein the I / O request exclusion unit confirms a priority route selectively set in advance for each I / O request whose occurrence is detected by each I / O request monitoring unit. And a means for preferentially issuing this input / output request using the priority route when it is confirmed by the priority route confirmation means that the priority route is set for a certain input / output request. I will do it.

[0011]

According to a first aspect of the present invention, a virtual device capable of directly handling an individual external storage device regardless of the management of the management means is generated from a program operating on a computer system, and a virtual device can be requested by the program. In response, an I / O request is issued to the virtual device, so that each external storage device itself can be recognized and directly accessed from the program operating on the system. Therefore, it is possible to test the external storage device itself immediately after the disk is exchanged from the program on the system.

According to a second aspect of the present invention, when a certain external storage device is used as a constituent element of a logical device under the control of the management means, the generation of a virtual device that accepts a write request to the external storage device is prohibited. Thus, it is possible to prevent the logical device management information from being substantially destroyed due to the rewriting and updating of the external storage device. Similarly, when a certain external storage device is used as a virtual device, prohibiting incorporation of the external storage device into a logical device that accepts a write request to the external storage device causes rewriting and updating of the external storage device. The virtual destruction of the virtual device can be prevented.

According to a third aspect of the present invention, in the background that a plurality of input / output paths capable of transmitting input / output requests to a common external storage device exist in a computer system, input / output requests to a logical device and input / output to a virtual device. By controlling to issue each I / O request exclusively when the requests occur simultaneously and the I / O requests are conditioned to be performed using different I / O paths, It is possible to prevent a situation in which I / O requests are simultaneously issued to a common external storage device, and thus data integrity in the external storage device can be guaranteed.

According to a fourth aspect of the invention, when a plurality of I / O requests using the same I / O path for a certain external storage device conflict, the I / O request for which the priority path is set has priority. It can be issued in a timely manner.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the arrangement of an external storage device management mechanism in the computer system of this embodiment.

As shown in FIG. 1, the external storage device management mechanism 1 is interconnected with a program interface 2, a storage subsystem 3, and a plurality of external storage devices 4. The external storage device management mechanism 1 includes an external storage device configuration management unit 11, an external storage device configuration information providing unit 12, an external storage device access management unit 13, an external storage device access unit 14,
Logical device configuration recognition unit 15, external storage device exclusion unit 1
6, a virtual device I / O request monitoring unit 17, an I / O request path exclusion unit 18, and a storage subsystem I / O request monitoring unit 19.

The external storage device configuration management section 11 recognizes each external storage device 4 connected to the system, and generates and manages configuration information such as its type, input / output path, and status. The external storage device configuration information providing unit 12 provides the external storage device access management unit 13 with reference to the configuration information of the external storage device 4 managed by the external storage device configuration management unit 11. Based on the configuration information of the external storage device 4, the external storage device access management unit 13 allows the program 5 operating on the system to directly handle each external storage device 4 regardless of the management of the storage subsystem 3. New virtual device. The external storage device access unit 14 performs an input / output request issuing process for the external storage device 4 defined as a virtual device. The logical device configuration recognition unit 15 is a means for confirming whether the external storage device 4 is currently used under the control of the storage subsystem 3, and is a logical device currently under the control of the storage subsystem 3 obtained from the storage subsystem 3. The above confirmation is performed based on the configuration information of. The external storage device exclusion unit 16 is means for exclusively controlling the use of the common external storage device 4 between the virtual device and the logical device as necessary. Virtual device I / O request monitoring unit 1
Reference numeral 7 monitors the generation of an input / output request from the external storage device access unit 14 to the external storage device 4 defined as a virtual device. The storage subsystem input / output request monitoring unit 19 monitors the generation of input / output requests from the storage subsystem 3 to the external storage device 4 defined as a logical device. The input / output request path exclusion unit 18 exclusively controls the issuance of the input / output request to the virtual device and the input / output request to the logical device using different input / output paths.

Next, the relationship between the logical device and the virtual device will be described with reference to FIG. As shown in the figure, the logical device 21 includes one or more external storage devices 4.
The storage subsystems 3a, 4b, and 4c divide the storage area into several areas A to I, and the storage subsystem 3 manages the divided areas as an arbitrary combination. At this time, it is possible to combine two divided areas having the same capacity to form a pair and mirror the logical device. In the illustrated example, the divided areas A, C of the external storage devices 4a, 4b,
A logical device 21 is generated with D as a constituent element, and a mirror device 21 'is generated with divided areas F, G, and H of the external storage devices 4b and 4c as constituent elements.

The storage subsystem 3 manages the areas of these external storage devices 4a-4c by using the external storage devices 4a-4c.
This is performed using the management information recorded in the management areas 22a to 22c. The management areas 22a to 22c store position information and the like of each of the divided areas A to I in its own external storage device.

In a computer system that manages the external storage device 4 using this storage subsystem 3,
When the program 5 accesses the external storage device 4,
An I / O request will be issued to the logical device. For example, the area X in the logic device 21 shown in FIG.
Is defined as a region of size y from the block offset x of the logical device 21. When actually making an input / output request to the external storage device 4, the storage subsystem 3 targets the area of size y from the block offset z of the area D of the actual external storage device 4b based on the information of the management area. Generate and issue an I / O request to Therefore, as long as the storage subsystem 3 manages the external storage device 4 in this manner, the program 5 operating on the system cannot directly issue an input / output request to the external storage device 4. Further, as a matter of course, the program cannot directly access the management areas 22a to 22c used in the storage subsystem 3.

Therefore, in this embodiment, the virtual device 23 of the external storage device 4 is generated so that the program 5 running on the system recognizes each external storage device 4 itself and can directly access the external storage device 4. That is, the program 5 is issued by issuing an input / output request to this virtual device.
It is possible to directly access the external storage device 4. The virtual device 23 is generated for each external storage device 4 in a one-to-one correspondence.

Next, the overall operation of this embodiment will be described with reference to the flowchart of FIG.

When a predetermined installation process for connecting the external storage device 4 to the system and making it usable is performed, the external storage device configuration management unit 11 is activated to generate the configuration information of the external storage device 4. (Step 30)
1). Subsequently, the external storage device configuration information providing unit 12 follows the request from the program 5 and the external storage device configuration management unit 11
Then, the above configuration information is taken out and provided to the external storage device access management unit 13 (step 302).

Thereafter, the external storage device access management unit 13
Receives a virtual device generation request for a certain external storage device 4 from the program 5 (step 303),
The external storage device exclusion unit 16 is inquired whether or not the virtual device can be currently generated. The external storage device exclusion unit 16 obtains the logical device configuration information from the logical device configuration recognition unit 15 and determines whether the external storage device 4 that is going to be made into a virtual device is currently used by the storage subsystem 3 based on this. If it is not in use, the access management unit 13 is permitted to generate a virtual device (step 304). The details of the exclusive processing of the external storage device will be described later.

When the access management unit 13 obtains the permission to generate the virtual device, the access management unit 13 generates the virtual device (step 30).
5). After the virtual device is generated, the external storage device access unit 14 can issue an input / output request to this virtual device as well, which allows the program 5 operating on the system to directly access the external storage device 4 itself. Will be possible. When an input / output request for a virtual device is issued from the external storage device access unit 14 (step 306), the request is detected by the virtual device input / output request monitoring unit 17 and notified to the input / output request route exclusion unit 18. Then, the I / O request path exclusion unit 18 performs an exclusion process for the I / O request for the virtual device and the I / O request for the logical device from the storage subsystem 3 (step 307). The exclusive processing of this input / output request will be described later in detail.

Next, details of the external storage device exclusion processing will be described with reference to the flowchart shown in FIG.

The external storage device exclusion unit 16 receives an exclusion processing request from not only the external storage device access management unit 13 but also the storage subsystem 3. The exclusive processing request from the storage subsystem 3 is issued when the storage subsystem 3 tries to incorporate a certain area of the external storage device 4 into a logical device.

Then, the external storage device exclusion unit 16 first checks whether or not the received request is from the storage subsystem 3 (step 401). If the request is from the storage subsystem 3, it is confirmed whether or not the external storage device 4 is currently used as a virtual device (step 402). If not, the external storage device 4 is configured as a logical device. It is allowed to be incorporated as an element (step 403). Further, if the external storage device 4 is being used as a virtual device, whether the logical device to be created in the storage subsystem 3 from now on is an exclusive use type logical device that grants a write request to the external storage device 4 is determined. Confirm (Step 40
4) If it is an exclusive use type logical device, it ends as an error (step 405). If it is not an exclusive use type logical device (if it is a logical device that allows only the read request to the external storage device 4), then the external storage device 4
External storage device 4 even if is used as a virtual device
Is allowed to be incorporated as a component of the logical device (step 403).

On the other hand, when it is determined in step 401 that the exclusive processing request is from the external storage device access management unit 13, the exclusive unit 16 determines that the virtual device to be generated is an exclusive use type virtual device. It is checked whether or not (step 406). When the virtual device is not the exclusive use type virtual device, the external storage device access management unit 13 is permitted to generate the virtual device (step 40).
7). If it is a virtual device of exclusive use type, the exclusion unit 16 checks whether or not the external storage device 4 is currently being used in the storage subsystem 3 (step 408), and if it is not being used, creates a virtual device to the external storage The device access management unit 13 is permitted (step 407). If it is in use, the process ends as an error (step 405).

Thus, when a certain external storage device 4 is used as a constituent element of a logical device under the control of the storage subsystem 3, generation of an exclusive use type virtual device for this external storage device 4 is prohibited. As a result, it is possible to prevent the management information in the storage subsystem 3 from being substantially destroyed when the external storage device 4 is rewritten and updated. Similarly, when a certain external storage device 4 is used as a virtual device, prohibiting incorporation of the external storage device 4 into an exclusive use type logical device for this external storage device 4 allows It is possible to prevent the virtual device from being substantially destroyed due to the update.

Next, details of the input / output request exclusion process will be described.

FIG. 5 is a diagram showing the configuration of a computer system which is a prerequisite for performing this input / output request exclusion processing.

In the computer system shown in the figure, 71 is a processor equipped with the external storage device management mechanism 1, and this processor 71 is a system bus 72.
Is connected to a plurality of input / output control devices 73a and 73b via. One input / output control device 73a is the input / output bus 7
4a through multiple bus interfaces 75a, 75c
The other input / output control device 73b is connected to a plurality of bus interfaces 75b, 7b via an input / output bus 74b.
It is connected to 5d. And each bus interface 7
5a to 75d are input / output control devices 73a and 73b, respectively.
It is managed by. In addition, the bus interface 75
a and 75b have a plurality of common external storage devices 76a,
76b is connected, and bus interfaces 75c and 75d
A plurality of common external storage devices 76c and 76d are connected to both.

That is, in this configuration, for example, the input / output path for the external storage device 76a is 73a → 74a → 75.
All individual external storage devices 76 such that there are two ways: a → 76a and 73b → 74b → 75b → 76a.
Two input / output paths are provided in each of a, 76b, 76c, and 76d.

Here, the path of the I / O request issued to the logical device from the storage subsystem 3 is one no matter how many paths exist so that the path can be identified when an error occurs due to the I / O request. It is fixed and used. The other route is used as an alternative route by the recovery process. Therefore, although there are two input / output paths for each external storage device, either one of them is preferentially used. Here, the storage subsystem 3
It is assumed that the priority path of the input / output request issued from the external storage device 76a is 73a → 74a → 75a → 76a.

On the other hand, in the virtual device, the input / output path can be selected from the program. Therefore, an input / output request for a virtual device may be issued using a path different from the input / output path for the logical device, and in this case, the following input / output request exclusive processing is required.

The procedure of the input / output request exclusion process will be described below with reference to the flowchart of FIG.

When the I / O request path exclusion unit 18 knows that any I / O request A to the virtual device or logical device is about to be issued, it first determines whether there is a request B currently being processed. Check (Step 5
01). If there is a request B being processed, the exclusion unit 18 checks whether the route used by the request B being processed is the same as the route used by the request A to be issued (step 502). If both routes are different,
Request A, which is about to be issued, is suspended (step 503). If both routes are the same, the exclusion unit 18 confirms whether the request A to be issued from now uses the priority route (step 50).
4) If the priority route is used, the request A is issued (step 505). If the request A does not use the priority route, the exclusion unit 18 checks whether another request C currently trying to use the priority route is on hold (step 506). The request A that is about to be issued is suspended (step 503). If the request C is not on hold, the request A is issued (step 505).

On the other hand, when it is determined in step 501 that the request B currently being processed does not exist, the exclusion unit 18 checks whether or not the request C currently held is present (step 507). If not, request A is issued (step 505). If there is a pending request C, it is checked whether the request A to be issued and the currently pending request C use the same route (step 508). If the same route is used, the pending request C is first issued (step 509), and then the current request A is issued (step 505). If the routes of both requests are different, the exclusion unit 18 checks whether the request A to be issued from now uses the preferential route (step 51).
0), if the priority route is used, the request A is issued as it is (step 505). If the priority route is not used, the pending request C is issued (step 511) and the current request A is held (step 503).

Next, in the above input / output path exclusion processing,
The process of issuing the pending input / output request will be described with reference to the flowchart of FIG. This process is operated when a completion notification of an input / output request is received, a timer interrupt, or the like.

This processing is effective when a pending input / output request occurs. When the pending input / output request C occurs (step 601), it is checked whether there is a request B currently being processed (step 602). When the request B currently being processed does not exist (in the case), the pending request C is issued regardless of whether the priority route is used (steps 603, 604, and 605).

On the other hand, if there is a request B currently being processed, it is checked whether this request B uses a priority route (step 606). If a priority route is used (in the case), step 603. Then, it is judged whether or not the hold request C uses the preferential route, and if it does not use the preferential route, the processing is terminated (step 607). If the hold request C uses the priority route, the hold request C is issued (step 604).

Further, if there is a request B currently being processed and this does not use the preferential route (in the case of), it is judged at step 603 whether or not the hold request C uses the preferential route, and the preferential route is determined. If the reservation request C does not use the priority route, the request C is issued (step 605).

In this way, when there is an input / output request that uses the priority route, the issuing order of the input / output requests is controlled so that the request is executed as much as possible.

[0046]

As described above, according to the computer system of the present invention, in a computer system having means for managing an external storage device as a logical device, the external storage device itself is recognized from a program operating on this system. Can be accessed. Therefore, it is possible to test the external storage device itself immediately after the storage medium is replaced from the program on the system.

Further, according to the present invention, when a certain external storage device is used as a constituent element of a logical device under the control of the management means, the generation of a virtual device which accepts a write request to the external storage device is prohibited. Thus, it is possible to prevent the logical device management information from being substantially destroyed due to the rewriting and updating of the external storage device. Similarly, when a certain external storage device is used as a virtual device, prohibiting incorporation of the external storage device into a logical device that accepts a write request to the external storage device causes rewriting and updating of the external storage device. The virtual destruction of the virtual device can be prevented. Further, according to the present invention, in the background that a plurality of input / output paths capable of transmitting input / output requests to a common external storage device exist in a computer system, an input / output request for a logical device and an input / output request for a virtual device are simultaneously performed. When an I / O request occurs and these I / O requests are conditioned to be performed by using different I / O paths, the I / O requests are controlled to be exclusively issued, so that a common external It is possible to prevent a situation in which I / O requests are simultaneously issued to the storage device, and thus it is possible to guarantee data integrity in the external storage device.

Further, according to the present invention, when a plurality of I / O requests using the same I / O path for a certain external storage device conflict, the I / O request for which the priority path is set has priority. It can be issued in a timely manner.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an external storage device management mechanism of a computer system according to this embodiment.

FIG. 2 is a diagram for explaining a relationship between a logical device and a virtual device in this embodiment.

FIG. 3 is a flowchart showing the overall operation procedure of this embodiment.

FIG. 4 is a flowchart showing a procedure of external storage device exclusion processing.

FIG. 5 is a diagram showing a configuration of a computer system of this embodiment including a plurality of input / output paths with an external storage device.

FIG. 6 is a flowchart showing a procedure of input / output request exclusive processing.

FIG. 7 is a flowchart showing a procedure of issuing processing of a pending input / output request.

[Explanation of symbols]

1 ... External storage device management mechanism, 2 ... Program interface, 3 ... Storage subsystem, 4 ... External storage device, 5 ...
Program, 11 ... External storage device configuration management unit, 12 ... External storage device configuration information providing unit, 13 ... External storage device access management unit, 14 ... External storage device access unit, 15 ... Logical device configuration recognition unit, 16 ... External storage Device exclusion unit, 17
... virtual device I / O request monitoring unit, 18 ... I / O request path exclusion unit, 19 ... storage subsystem I / O request monitoring unit,
21 ... Logical device, 23 ... Virtual device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06F 13/12 340 7368-5E G06F 13/12 340H

Claims (4)

[Claims] 1. A computer system having a management means for dividing a storage area of each of a plurality of external storage devices into a plurality of areas and selectively combining these divided areas to generate and manage one or more logical devices; A configuration information generating means for generating physical configuration information of the external storage device, and a program operating on a computer system based on the physical configuration information of the external storage device generated by the configuration information generating means. A virtual device generation unit that generates a virtual device that can directly handle each of the external storage devices regardless of the management of the management unit, and a virtual device generation unit that generates a virtual device in response to a request from the program. And a virtual device access means for issuing an input / output request for the virtual device. system. 2. The computer system according to claim 1, wherein when a certain external storage device is used as a component of said logical device under the control of said management means, said write request to said certain external storage device is acknowledged. A means for prohibiting generation of a virtual device and prohibiting incorporation of the external storage device into the logical device that allows a write request to the certain external storage device when the certain external storage device is used as the virtual device. A computer system further comprising: 3. The computer system according to claim 1, wherein a plurality of input / output paths capable of transmitting an input / output request for the common external storage device, and an input / output request for the logical device from the management unit are provided. A logical device I / O request monitoring unit that monitors the occurrence, a virtual device I / O request monitoring unit that monitors the occurrence of the I / O request to the virtual device, and an input / output unit that detects the occurrence by each I / O request monitoring unit. When the output request is for the common external storage device, a route confirmation unit for confirming the input / output routes set in advance for each of the input / output requests, and each input unit confirmed by the route confirmation unit. When the routes of the output requests are different, an input / output request exclusion means for controlling the issuance of each of the input / output requests is provided. Computer system characterized by comprising the al. 4. The computer system according to claim 3, further comprising priority route setting means capable of arbitrarily setting a priority route among the plurality of input / output routes for the individual input / output requests, Entry output request exclusion means, priority route confirmation means for confirming a priority route set for the input / output request detected by each of the input / output request monitoring means, and the priority route confirmation means for the priority route And a means for preferentially issuing an input / output request that is confirmed to be set using the priority route.