JP2009251735A - Method and system for accelerating file system in virtual computer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and system for processing a storage access request from a process on a guest OS (operating system) at high speed in a virtual computer system to improve its performance. <P>SOLUTION: When an access request is made to the file system from the process 30, the access request is accepted by an access request converting means 14 on a host OS 10 and discriminated whether it can be directly processed in the file system 11 of the host OS. If the access request can be directly processed, processing is taken over by the file system 11 of the host OS 10, and a storage device 45 is accessed through a disk system 12. If the access request cannot be directly processed in the file system 11 of the host OS, the request is transferred to a file system 21 on the guest OS 20, and the storage device 45 is accessed through both the guest OS and host OS in the same way as an existing virtual computer system. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a virtual machine system, and more particularly, to a virtual machine system with a faster file system and a method for speeding up the file system.

  In recent years, virtual computers such as running old programs as they are on new computer hardware, or operating servers operating on different operating systems (OS) as they are on one computer hardware The range of applications is expanding.

  The virtual computer implements virtual hardware on an operating system (referred to as “host OS”) that runs on computer hardware such as a CPU and a memory, and the virtual hardware and the operating system that runs on the hardware. (Referred to as a “guest OS”), and it is possible to improve the operating rate and operability of hardware resources by executing processes (application programs and the like) that operate on the OS.

  In such a virtual machine, the virtualization technology for eliciting its convenience causes performance overhead and greatly affects the practicality. For example, since a program (process) operating on the guest OS performs input / output processing (I / O processing) for a storage device such as a disk device or an input / output device, it is also called an I / O access request (“access request”). First, after the access request is interpreted and converted in the guest OS, the access request is issued to the host OS. In this case, the access request is issued to the actual hardware after the access request is interpreted and converted in the host OS.

  For this reason, the I / O processing in the virtual machine has a disadvantage in that the performance is deteriorated, for example, it takes longer time than the OS and the program running on the real machine.

  When a process on the OS accesses the file system, in general, in a computer, since the OS shifts from the user mode to the kernel mode (privileged mode), it takes time for the mode shift processing. In the virtual machine, when a process operating on the guest OS accesses the file system, two kernel modes are used when the process shifts from the process to the guest OS and when the process shifts from the guest OS to the host OS. Transition takes place. Therefore, the kernel mode shift is performed once more than in the case of a real computer, and the file access on the virtual computer has a problem that the performance deteriorates.

  As a specific example related here, there is a file system virtualization technique disclosed in Patent Document 1. This system includes an application program, an input / output system service, a virtual file system conversion driver, a file system driver, a disk driver, and the like, and operates as follows. In other words, when a file system request is issued from the application program to the input / output system service, the virtual file system conversion driver converts the file system request and transmits the input / output request to the file system driver, so that the disk device etc. Provides virtual files that virtualize the hardware characteristics.

Patent Document 2 discloses a technology that uses a virtual computer as a virtual server emulator. This system includes a virtual server, a virtual server control unit, a hard disk emulator unit, a hard disk, and the like, and the virtual server includes a virtual BIOS, a driver group, and an application. In the operation of this file system, when an application accesses the file system, the driver group processes the input / output request, the request is transmitted to the virtual BIOS, and the input / output request issued by the virtual BIOS is processed by the virtual server. The input / output request is interpreted and transmitted to the hard disk emulator unit, and the input / output request is executed to the hard disk.
JP 2001-229056 A JP 2001-195270 A

  However, since the virtual machine is not provided in the configuration disclosed in Patent Document 1 described above, when a plurality of virtual machines are executed as the guest OS, there is a disadvantage that the file systems cannot be shared.

  In the configuration disclosed in Patent Document 2 described above, the conversion to input / output request processing is executed by the virtual BIOS and the hard disk emulator unit on the virtual server, so that the access performance to the hard disk device is reduced. The file access problem on the virtual machine mentioned above has not been solved.

  As described above, in the virtual machine, a request for accessing the file system from a process on the guest OS is processed by the file system of the guest OS of the virtual machine and the host OS of the real machine. It took time for the conversion from the user mode to the kernel mode twice, and there was a problem that the performance deteriorated as compared with the file system access in the actual computer (host OS).

(Object of invention)
In view of the above problems, the present invention provides a virtual machine system and method for processing a storage access request from a process on a guest OS at high speed, and an object thereof is to improve the performance of the virtual machine system. .

  In order to solve the above problems, a virtual machine system according to the present invention includes a first operating system that operates on a computer hardware including at least a CPU, a memory, and a storage device, and the first operating system. A second operating system that operates, and a process that operates on the second operating system, receives an access request to the storage device from the process, and sends the access request to the first operating system The first operating system is provided with access request conversion means for converting the file system so as to conform to the file system provided in the first operating system.

  In order to solve the above-mentioned problem, a storage access method according to the present invention includes a first operating system that operates on computer hardware including at least a CPU, a memory, and a storage device, and the first operating system. A virtual machine system comprising a second operating system operating on the system and a process operating on the second operating system, wherein the process accesses the storage device when the process is accessed A first step of accepting an access request to the storage device from the first operating system, and determining whether the access request can be processed by the first operating system based on file system correspondence information 2 steps And a third step of converting the access request so as to be compatible with the file system of the first operating system when it is determined in the second step that it can be processed by the first operating system. It is characterized by that.

  Furthermore, in order to solve the above-described problem, a storage access program according to the present invention includes a first operating system that operates on computer hardware including at least a CPU, a memory, and a storage device, and the first operating system. A virtual machine system comprising a second operating system operating on a system and a process operating on the second operating system, wherein an access request from the process to the storage device is sent to the first operating system An access request reception function received by the operating system, an adaptability determination function for determining whether the received access request can be processed by the first operating system based on the file system correspondence information, and the adaptability determination function The When it is determined that the access request can be processed by the first operating system, the computer is caused to execute an adaptive conversion processing function for converting the access request to conform to the file system of the first operating system. It is characterized by comprising.

  Since the present invention is configured as described above, it is possible to increase the processing speed of the access request to the storage from the process on the guest OS, which contributes to the enhancement of the performance of the entire virtual machine system.

  Next, a virtual machine system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a basic hierarchical configuration of the virtual computer system 1.

  In FIG. 1, a virtual computer system 1 includes a computer hardware 40 such as a CPU, a memory, and a storage device (secondary storage device) 45, and a host OS (first operating system) that is a program operating on the computer hardware 40. 10 and a guest OS (second operating system) 20 which is a program process operating thereon, and a process 30 such as an application program operating thereon.

  A host OS (first operating system) 10 includes a file system 11 that provides a file system service to a program process that runs on the host OS, and a storage device (specifically, a disk device) 45 from the file system 11. And a file system information 13 which is referred to as correspondence information when the file system 11 accesses the disk system 12.

  Further, the host OS 10 is provided with access request conversion means 14 that mediates an access request from the process 30 on the guest OS 20 to the file system 11, and file system correspondence information 15 that the means 14 refers to in the conversion process. It has been. These are important elements that realize the high-speed file access characteristic of this virtual machine system, and will be described in detail later.

  The guest OS (second operating system) 20 is a process that operates on the host OS 10. A file system 21 that provides a file system service to a program process that operates on the guest OS 20, and the file system 21 Disk system 22 that processes access to the disk device, file system information 23 that is referred to as correspondence information when the file system 21 accesses the disk system 22, and the file system 11 that is recognized as a storage device from the disk system 22. And the virtual storage device 16 provided by.

  The process 30 is an application program or a system utility program, and stores information using a file system service provided by the host OS 10 or the guest OS 20 in order to permanently hold or use the information as necessary. The data is stored in the device 45 and read out.

  Here, the configuration of the access request conversion unit 14 described above will be described with reference to FIG. FIG. 2 shows a functional block configuration of the access request conversion means 14.

  In FIG. 2, the access request conversion means 14 includes an access request reception function 14 </ b> A that receives an access request from the process 30 on the guest OS 20 from the guest OS 20, and the received access request is the host OS 10 or guest OS 20. Which operating system should be processed based on the file system correspondence information 15 and a conversion function 14C for converting an access request based on the determination result. For this reason, the access request from the process 30 can be directly processed by the file system 11 of the host OS 10, and the speed of file access can be increased. In the present embodiment, the access request conversion means 14 is a component of the host OS, and its substance is a program.

  The virtual computer system 1 having the above-described configuration receives an access request to the storage apparatus 45 from the process 30 on the guest OS 20 and sends the access request to the file system 11 provided in the host OS (first operating system) 10. Since the host OS (first operating system) 10 is provided with the access request conversion means 14 that converts it so that it conforms, the access request needs to be interpreted only once in the host OS 10, not in the guest OS 20. For this reason, the conversion from the user mode to the kernel mode, which takes time, can be performed only once in the host OS 10 and the speed of file access can be increased, leading to improvement in the performance of the entire virtual computer system.

  The virtual computer system 1 is installed in the host OS (first operating system) 10 so that the file system correspondence information 15 can be used, and the access request conversion means 14 processes the access request from the process 30 by the host OS 10. It can also be configured to determine whether or not it can be performed based on the file system correspondence information 15. At this time, if it is determined that the access request has contents that can be processed by the host OS 10, the access request is converted so as to conform to the file system 11 provided in the host OS 10. If it is determined that the host OS 10 cannot process the access request, the access request can be converted back into the file system 21 of the guest OS (second operating system) 20 and sent back.

  As a result, when the access request can be processed directly by the host OS 10, the host OS 10 performs the processing. When the access request cannot be processed directly by the host OS 10, the processing can be performed via the file system 21 of the guest OS 20. The scope of application of computer systems is expanded. Further, only when it is determined that the access request cannot be processed by the host OS 10, it is processed by the file system 21 of the guest OS 20, so that file access can be speeded up. These points will also be described in detail.

(Description of operation)
Regarding the access operation to the file system in the virtual computer system 1, first, a basic operation flow will be described, and then detailed description will be given. FIG. 3 shows a basic access operation flow to the file system.

  In the virtual computer system 1 of FIG. 3, first, when an access request is issued to access the file system from the process 30 on the guest OS 20, it is accepted by the access request conversion means 14 of the host OS 10 as indicated by a solid line arrow. It is done. Then, it is determined which of the two operating system file systems 11 and 21 should process the access request. When the file system 11 of the host OS 10 can directly process the access request, the access request is converted so as to be compatible with the process of the file system 11 of the host OS 10, delivered to the file system 11 on the host OS 10, and passed through the disk system 12. Finally, the storage apparatus 45 is accessed.

  As a result, as compared with the existing file access method indicated by the dotted arrow, since there is no passing through the file system 21 of the guest OS 20, the interpretation of the access request that is normally required twice is performed in the file system 11 of the host OS 10. The conversion from the user mode to the kernel mode, which only takes one time, can be performed only once by the host OS 10, so that an effect of enabling high-speed file access can be obtained.

  If the access request cannot be directly processed by the file system 11 of the host OS 10, the request is transferred to the file system 21 of the guest OS 20, and the guest OS and the host OS are used as in the existing virtual machine system. The storage device 45 is accessed. If the ratio of the files that cannot be directly processed by the file system 11 of the host OS 10 is small, the overall file access performance is improved.

  Next, the basic operation flow described above will be described in more detail with reference to FIG. FIG. 4 shows a detailed flowchart of the file access operation flow.

  As shown in FIG. 4, in the file access operation of the virtual computer system 1, first, the process 30 on the guest OS 20 issues an access request to access the file system (step S100).

  This access request is for the guest OS 20 (system call). In this case, all the access requests (system calls) are transferred as access requests (system calls) to the host OS 10 in the present system 1 (step S101).

  This access request is accepted by the access request conversion means 14 of the host OS 10 (access request accepting step, first step). Then, the access request conversion means 14 determines whether the access request can be processed by the file system 11 of the host OS 10 or needs to be analyzed by the file system 21 of the guest OS 20 based on the file system correspondence information 15. (Step S102, adaptability determination step, second step).

  Here, as shown in FIG. 5, the file system correspondence information 15 is a correspondence table including columns of a requesting guest OS name, a requesting file system, and file system information in the converted host OS 10. (Table) is held on the memory. For example, when an access request to the access request conversion unit 14 is received, the file system correspondence information 15 is referred to, and the host OS 10 after conversion is converted from the line where the requesting guest OS name and the requesting file system match. File system information is retrieved and converted to match the access request. Further, when a read access request is made and there is no line in which the requesting guest OS name and the requesting file system match, or there is no file system information in the converted host OS 10 even if they match, Since the host OS 10 cannot perform processing in the file system 11, the access request is sent back to the guest OS 20.

  Next, when it is determined that the guest OS 20 needs to process, the access request is transferred to the file system 21 of the guest OS 20 (step S103, access request return step), and the file system 21 and the disk system 22 of the guest OS 20 are transferred. Thus, the request is processed (step S104). In this case, a process is further issued to the host OS 10 that provides the storage device service to the guest OS 20 (step S105). Steps S103 to S105 are the same as the existing method, and by providing these processing steps, it becomes possible to respond to an access request from the process 30 that cannot be directly processed by the file system 11 on the host OS 10.

  If the access request conversion means (program) 14 determines that the host OS 10 can directly execute the processing, the access request conversion means 14 makes an access request to the request source guest OS 20 and the requested file system information. Based on this, the file system information in the host OS 10 after conversion is acquired from the file system correspondence information 15 and converted as an access request in the host OS 10 based on the information (step S106, conformity conversion step, third step) The request is transferred to the file system 11 of the host OS 10.

  This step S106 eliminates the need to go through the file system 21 on the guest OS 20, so that the interpretation of the access request is reduced to one time, and the transition from the user mode to the kernel mode is only required once in the host OS 10, Switching time to the kernel mode can also be shortened, and high-speed access requests can be achieved.

  The access request issued in step S105 or step S106 is analyzed by the file system 11 of the host OS 10 (step S107) and converted into a request for the disk system 12 as an access request to the storage apparatus 45 (step S108). An access request to the storage device 45 is executed. This completes the processing of the file access request from the process 30.

  Subsequently, the basic operation flow of the operation of the virtual computer system 1 after the processing of the access request to the storage apparatus 45 is completed will be described first, and then described in detail.

  FIG. 6 is a diagram for explaining the basic operation flow after the access operation to the storage apparatus 45 in the virtual computer system 1 is completed.

  In FIG. 6, when the access request to the storage device 45 is completed, the file system 11 on the host OS 10 processes the completion notification, and then the completed access request is requested via the file system 21 of the guest OS 20. Or whether it is issued directly from the access request conversion means 14 to the file system 11.

  Depending on the result, the processing result is returned to the guest OS 20 that is the access request issuing source, or the processing result is transmitted to the access request conversion means 14, and the access request conversion means 14 performs processing in the host OS 10 from the file system correspondence information 15. Convert as a request and return the result to process 30.

Next, a detailed operation after the above access request is completed will be described with reference to FIG. FIG. 7 shows a detailed flowchart thereof.
In FIG. 7, when the request for the storage apparatus 45 is completed, the disk system 12 first notifies the file system 11 that the request has been completed (step S201).

  After processing the completion notification (step S202), the file system 11 checks whether the completed request is issued from the process 30 on the guest OS 20 through the file system 21 of the guest OS 20 (step S203).

  If it is issued via the file system 21 of the guest OS 20, the result is returned to the guest OS 20 that is the access request issuing source (step S204), and the disk system 22 and the file system 21 in the guest OS 20 are processed. (Step S205), and finally the result is returned to the process 30 that is the access request issuer (Step S207).

  If the completed request has been requested to the file system 11 through the access request conversion means 14, the file system 11 transmits the processing result to the access request conversion means 14, and the access request conversion means 14 Based on the guest OS 20 and the requested file system, the file system correspondence information 15 is converted into a processing request in the host OS 10 (step S206), and the result is returned to the process 30 (step S207).

  With the above operation, the result of the storage operation by the access request from the process 30 on the guest OS 20 is returned to the process 30, and the file access operation is completed.

Here, the method including the first step, the second step, and the third step in the operation of the virtual computer system 1 described above is one storage access method in the virtual computer system.
That is, the storage access method includes a first step of accepting an access request from the process 30 to the storage device 45 by the host OS (first operating system) 10, and the access request is received by the host OS (first operating system). ) A second step of determining whether or not processing can be performed on the basis of the file system correspondence information 15 and a case where it is determined that processing can be performed on the host OS (first operating system) 10 in this second step. And a third step of converting the access request so as to be compatible with the file system 11 of the host OS (first operating system) 10.

  As a result, since there is no transit operation to the file system 21 on the guest OS 20, it is only necessary to interpret the access request that was required twice, and conversion to the kernel mode, which takes time, is also converted by the host OS. Since only one time is required, the effect of enabling high-speed file access is obtained.

  Further, as another storage access method, if it is determined in the second step that the host OS (first operating system) 10 cannot process, an access request is issued to the guest OS (second operating system). ) An access request sending back step (step S103) may be added to convert and send back to match the 20 file systems 21.

  As a result, it is possible to respond to an access request from the process 30 that cannot be directly processed by the file system 11 on the host OS 10. Then, the virtual computer system 1 can process the access request to the file system from the process 30 on the guest OS as a whole at high speed.

  Here, the storage access program is a program in which the processing functions of the access request receiving process, the adaptability determining process, and the adaptive conversion process described above are programmed to run on the computer hardware 40. FIG. 8 shows a flowchart of this storage access program.

  That is, in this virtual machine system, the storage access program receives an access request reception function 201 for accepting an access request from the process 30 to the storage apparatus 45 by the host OS (first operating system) 10, and the accepted access request. Is determined by the host OS (first operating system) 10 based on the file system correspondence information 15, and the adaptability determination function 202 makes an access request to the host OS (first operation system). If it is determined that the access request can be processed by the first operating system 10, the computer is caused to execute the adaptive conversion processing function 203 that converts the access request so as to conform to the file system 11 of the host OS (first operating system) 10. Yo Characterized by being configured to.

  Further, when it is determined that the host OS 10 cannot process in the execution process of the adaptability determination step in the description of the operation flow described above, the access request is converted and returned so as to be compatible with the file system 21 of the guest OS 20. Although a return process (step S103) is provided, the processing function of the access request return process may be added to the above-described storage access program.

  That is, the above-described storage access program functions when it is determined that the host OS 10 cannot process in the process of the adaptability determination function 202, and the access request is sent to the file system 21 of the guest OS 20 (second operating system). An access request return function 204 may be provided to convert and send it back so that it can be adapted to be executed by a computer.

  Thus, the storage access program performs the above-described processing specifically to speed up file access from the processes on the guest OS of the virtual machine system. The storage access program is substantially the same as the access request conversion unit 14 realized as a program.

  In the above description, for convenience of explanation, the guest OS 20 on the host OS 10 has been described as if it was one, but a plurality of different guest OSs may exist on one host OS. In such a virtual machine system, the file system access from the guest OS is converted into the file system access in the host OS, and all file system access request processing is executed in the single host OS. . For this reason, not only the same file system can be shared between the host OS and guest OS, but also the same file system can be shared between a plurality of guest OSs through the host OS's only file access request processing. It has the merit that it can be shared.

The effects of the virtual computer system based on the above configuration and operation are as follows.
This virtual machine system is configured so that when the host OS can execute file system processing for a process on the guest OS, processing in the file system and disk system in the guest OS does not occur. Time-consuming file system request analysis and disk system request analysis can be omitted, and only one mode transition from user mode to kernel mode is required, reducing processing time and improving system performance. I can plan.

  In the virtual machine system, the file system access from the guest OS is converted into the file system access in the host OS, and all file system request processing is executed in the host OS. The same file system can be shared between the OS and the guest OS.

  Furthermore, this virtual computer system has an effect that the same file system can be shared among a plurality of guest OSes. This is because the file system sharing between the guest OS and the host OS is realized as described above, and the file system can be shared among a plurality of guest OSs by using this.

  Further, the present invention can be applied to general uses such as improving the performance of a file system when a virtual computer is executed by an emulator. Further, the present invention can be applied to a use such as sharing a file system among a plurality of virtual machines.

It is a block diagram which shows the hierarchical structure of the virtual machine system which concerns on one Embodiment of this invention. It is a functional block block diagram of an access request conversion means. FIG. 2 is a diagram for explaining a basic operation flow of file access of the virtual machine system disclosed in FIG. FIG. 4 is a detailed flowchart of the file access operation disclosed in FIG. 3. It is a correspondence table (table) which shows the composition of file system correspondence information. FIG. 2 is a diagram for explaining a basic operation flow after a file access request of the virtual machine system disclosed in FIG. 1 is completed. FIG. 7 is a flowchart of the operation after the completion of the file access request disclosed in FIG. 6. It is a flowchart figure of the program for storage access.

Explanation of symbols

1 Virtual computer system 10 Host OS (first operating system)
11 File system 12 (on host OS) Disk system 14 (on host OS) Access request conversion program (access request conversion means)
14A Access request accepting function 14B Discriminating function 14C Conversion function 15 File system correspondence information 16 Virtual storage system 20 Guest OS (second operating system)
21 File system 22 (on guest OS) Disk system 30 (on guest OS) Process 40 Computer hardware 45 Storage device 201 Access request reception function 202 Adaptation determination function 203 Adaptation conversion function 204 Access request return function

Claims (8)

A first operating system that operates on computer hardware including at least a CPU, a memory, and a storage device, a second operating system that operates on the first operating system, and on the second operating system A virtual machine system comprising a process running on
An access request conversion unit that receives an access request to the storage device from the process and converts the access request so as to be compatible with a file system included in the first operating system, to the first operating system. A virtual computer system characterized by comprising. In the virtual machine system according to claim 1,
The first operating system is installed so that file system compatible information can be used,
The access request conversion means determines whether the access request is a content that can be processed by the first operating system based on the file system correspondence information, and the access request is determined by the first operating system. When it is determined that the content can be processed in step 1, the virtual computer system is configured to convert the access request so as to be compatible with the file system provided in the first operating system. In the virtual machine system according to claim 2,
When the access request conversion means determines that the access request from the process cannot be processed by the first operating system, the access request conversion means converts the access request to conform to the file system of the second operating system. A virtual computer system configured to return. In the virtual machine system according to claim 1, 2, or 3,
Based on the file system correspondence information, the access request conversion means determines whether the access request is accepted by the access request from the process, and whether the access request is to be processed by the first or second operating system. A virtual machine system comprising: a discrimination function for discrimination; and a conversion process for the access request based on the discrimination result. A first operating system that operates on computer hardware including at least a CPU, a memory, and a storage device, a second operating system that operates on the first operating system, and on the second operating system In the virtual machine system comprising the process operating in the storage access method for accessing the storage device from the process,
A first step of accepting an access request to the storage device from the process by the first operating system;
A second step of determining whether the access request can be processed by the first operating system based on file system correspondence information;
A third step of converting the access request so as to be compatible with the file system of the first operating system when it is determined in the second step that the first operating system can process it;
A storage access method characterized by comprising: The storage access method according to claim 5, wherein:
If it is determined in the second step that the first operating system cannot process, an access request return step for converting and returning the access request to be compatible with the file system of the second operating system is performed. An access method for storage, characterized by being provided. A first operating system that operates on computer hardware including at least a CPU, a memory, and a storage device, a second operating system that operates on the first operating system, and on the second operating system A virtual machine system comprising a process running on
An access request accepting function for accepting an access request to the storage device from the process by the first operating system;
An adaptability determining function for determining whether or not the accepted access request can be processed by the first operating system based on the file system correspondence information;
And an adaptive conversion process for converting the access request so as to conform to the file system of the first operating system when it is determined by the adaptability determining function that the access request can be processed by the first operating system. function,
A storage access program configured to cause a computer to execute the program. In the storage access program according to claim 7,
This function functions when it is determined that the first operating system cannot be processed in the process of executing the adaptability determination function, and converts the access request back into a file system of the second operating system and sends it back. Provide a request return function,
A storage access program configured to cause a computer to execute these.

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