JP5027939B1 - Host server with virtual storage for virtual machines - Google Patents

Abstract

[PROBLEMS] To improve the availability of storage of a virtual machine in a plurality of host servers on which the virtual machine operates, and to enable continuous access to the same storage when the virtual machine is moved to another host server. .
A plurality of host servers to which physical disks are connected each supply a physical storage accessible via a physical storage supply interface in the same host server, and operate on other host servers By the interface, the physical storage is collected as virtual storage and provided to the virtual machine.
[Selection] Figure 1

Description

The present invention relates to a storage connected to a virtual machine.

In recent years, virtualization technology that allows multiple independent virtual machines to operate simultaneously on a single host server has become widespread.

There is also a technology to configure multiple host servers and move them to other host servers when a host server fails or when a virtual machine is stopped or running according to the need for resources such as memory and CPU. It has been realized.

In order to move a virtual machine to another host server in this way, external storage that can be shared by a plurality of host servers is required in addition to the physical disk connected to the host server. (See Patent Document 1)

There is also a method called a storage grid in which a storage is configured by a large number of servers. This is a method of handling data distributed to a plurality of storages and servers for the purpose of handling a large amount of data that cannot be processed by a single server.

This storage grid requires a metadata server that records the address map, which is the location of the data, as metadata, and acquires data via the interface in this metadata server or whenever there is necessary data. The metadata of the data is acquired from the metadata server, the server having the data is specified, and the data is acquired by accessing the specified server. (See Patent Document 2)

JP 2010-033404 JP 2010-097563 A

However, the method using external storage is costly because it requires storage separately from the physical disk connected to the host server, and the failure of the external storage becomes the failure of all virtual machines. There was also a problem in availability.

In addition, in the storage grid, the metadata server tends to be a single point of failure, and there is a problem in availability as with external storage.

Accordingly, an object of the present invention is to reduce costs and improve system availability by using a physical disk connected to a host server, thereby eliminating the need for external storage.

In the present invention, a physical disk connected to a host server can be accessed from another host server via a network by a physical storage supply interface that is software or hardware that operates in the host server. It is configured as a virtual storage by a virtual storage configuration interface that is software that operates above, and is connected to a virtual machine.

Since the virtual storage configuration interface in the host server is software that runs on the host server, it cannot be the storage required to start the host server itself, but it must be the storage required to start the virtual machine. Can be

As metadata for associating virtual storage and physical storage, metadata necessary for a virtual machine on the host server is copied from the virtual storage control server to the virtual storage configuration interface.

The data recorded in the virtual storage is finely distributed and recorded on the physical disks of a plurality of different host servers. In this case, a method such as RAID 1 for recording the same data in two or more units, RAID 5 or RAID 6 for recording parity data is used.

According to the present invention, when a virtual machine is moved to run on another host server, it is possible to access the same physical disk as before the transfer via the virtual storage configuration interface of the destination host server. Become.

In addition, because a virtual storage configuration interface is installed in the host server for each virtual machine that uses the interface, even if a failure occurs in one host server, the virtual storage configuration interface of a virtual machine on another host server There is no failure.

Similarly, because the physical storage supply interface is distributed to multiple host servers, even if a failure occurs in one host server, it can be replaced by another host server, and the data is distributed by RAID. Because it is redundant, no failure occurs in the virtual storage.

Therefore, even if a failure occurs in a certain host server, it is easy to restart a virtual machine that was running on that host server on another host server.

The virtual storage control server may perform metadata operations when starting a virtual machine or rearranging physical storage, but the necessary metadata is copied to the virtual storage configuration interface when the virtual machine is started. It is not required for continued operation after startup.

Therefore, unlike the metadata server in the storage grid, the virtual storage control server is not a single point of failure.

Furthermore, such an improvement in storage availability can be performed without requiring a storage device other than the host server such as an external storage.

It is a block diagram which shows the hardware constitutions of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.

1 shows a physical disk 102, a virtual machine 103, a virtual storage configuration interface 104, a host server 100 including a physical storage supply interface 101, a virtual storage control server 110, a plurality of host servers 100, and a virtual storage control server. 1 is a block diagram illustrating a configuration of an information processing system including a network switch 120 that connects 110. FIG.

The virtual storage in the present application refers to the data recorded on the physical disk being fixedly arranged with regularity, while referring to the position where the data was recorded as metadata. Indicates storage that uses a recordable method.

In addition, the physical storage in the present application refers to a recording area where virtual storage data is actually written to a physical disk.

As metadata, there are a case where a mapping table in which a correspondence relationship between virtual storage and physical storage is recorded, and a case where the correspondence relationship is obtained by a predetermined calculation method.

The virtual storage configuration interface 104 is software that provides an interface recognizable as storage to the virtual machine 103. As this interface, for example, an iSCSI (Internet Small Computer System Interface) or an interface that can be used in the same manner as a local physical disk by a dedicated device driver is assumed.

Further, the virtual storage configuration interface 104 may not be in the same host server 100 as the virtual machine 103 but may be in another host server 100 and connected to the virtual machine 103 by one or a plurality of interfaces.

The physical storage supply interface 101 can read / write data from / to the physical disk 102 of the host server 100 and holds a plurality of virtual storages in the physical disk 102 as a number of subdivided data.

Further, by recording in the metadata or the physical disk 102 that no valid data has been recorded yet for each segmented data, the required capacity of the physical disk 102 can be reduced.

The access from the physical storage supply interface 101 to the physical disk 102 does not use the file system by the OS (Operating System) of the host server 100, but directly subdivides the physical disk area and uses the file system of the host server 100. A configuration in which an area created as a file is segmented and used, or a configuration in which a file is created and used for each segmented data required by the physical storage supply interface 101 on the file system of the host server 100 is considered. It is done.

Further, since the physical storage supply interface 101 can be an access process by simple mapping, it can be constructed by either software or hardware.

The virtual storage control server 110 is a server that holds all metadata indicating the correspondence relationship from the virtual storage to the physical storage.

When the virtual machine 103 is started up or moved to a different host server 100, the virtual machine 103 is required in the memory of the virtual storage configuration interface 104 or in the physical disk 102 from the virtual storage control server 110. The metadata that is assumed to be copied.

Further, the virtual storage control server 110 detects a failure of the physical storage supply interface 101, a failure of the physical disk 102, and a shortage of capacity, and moves to a physical disk 102 having a sufficient capacity connected to any normal physical storage supply interface 101. The virtual storage data recording position is rearranged and new metadata is notified to the virtual storage configuration interface 104.

However, the virtual storage configuration interface 104 or the physical storage supply interface 101 stores the metadata in the physical disk 102 by itself, and the virtual storage configuration interface 104 inquires the physical storage supply interface 101 to reallocate the physical storage. By adopting a method for securing the area, it is possible to adopt a configuration in which the virtual storage control server 110 is unnecessary.

Also, the virtual storage control server 110 is not required when the correspondence is obtained by a calculation method in which metadata is determined in advance.

A specific process for accessing the physical disk 102 from the virtual machine 103 will be described.

As described above, the virtual machine 103 recognizes the virtual storage configuration interface 104 as storage, and transmits a command to read or write data at a specific position in the virtual storage to the virtual storage configuration interface 104.

The location of the virtual storage data described in the command from the virtual machine 103 is information for identifying the host server 100 or the physical storage supply interface 101 that holds the data based on the metadata that the virtual storage configuration interface 104 has. And converted into information indicating a specific position of the physical disk 102.

When the host server 100 is specified from the metadata, there is only one physical storage supply interface 101 in the host server 100, or when there are a plurality of physical storage supply interfaces 101, the physical storage supply interface 101 is specified as one according to a predetermined rule. The physical storage supply interface 101 is also specified by selecting any one according to a mechanism that can be processed even when accessing the.

The virtual storage configuration interface 104 transmits an instruction to read or write data at a specific position on the physical disk 102 to the physical storage supply interface 101 specified by the metadata.

For reasons such as speeding up, redundancy, and high reliability, data recorded in the virtual storage may be arranged so as to be recorded in the physical disks 102 of the plurality of physical storage supply interfaces 101.

The physical storage supply interface 101 that has received the command reads or writes data at a specific position on the physical disk 102 and returns the result to the virtual storage configuration interface 104.

Further, the virtual storage configuration interface 104 returns the processing result returned from the physical storage supply interface 101 to the virtual machine 103 as a result of processing to the virtual storage.

Through the above processing, the virtual machine 103 can access the virtual storage as a storage.

100: Host server 101: Physical storage supply interface 102: Physical disk 103: Virtual machine 104: Virtual storage configuration interface 110: Virtual storage control server 120: Network switch

Claims (2)

A system in which multiple host servers that operate virtual machines are connected via a network switch,
A physical disk that holds multiple virtual storages as a number of fragmented data;
A physical storage supply interface that is software for making the data on the physical disk accessible via the network switch connected to the host server;
With respect to the virtual storage required for the virtual machine in the host server, the location information of a plurality of virtual storages held in a physical disk as a large number of subdivided data is referred to as metadata, via the network switch Virtual software that accesses the data of the physical storage supply interface on a plurality of the host servers and configures the virtual storage for the virtual machine from the data, and stores the metadata in a memory A storage configuration interface; and
A host server having the virtual machine operating on the host server and accessing the virtual storage configured by the virtual storage configuration interface;
A system having a virtual storage control server that holds all the metadata necessary for a plurality of the virtual storage configuration interfaces and controls copying and changing of the metadata.   The system according to claim 1, wherein the physical storage supply interface is configured by hardware.

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