JP2004326401A - Method and system for controlling storage device, and switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To return an appropriate response even to an acquiring command for a list of magnetic disk information issued to a logical volume composed of a plurality of magnetic disks different in support function. <P>SOLUTION: A switch capable of constituting the logical volume from the magnetic disks has a calculation method and fixed value information at each attribute for inquiry about the logical volume from a host device, thereby unifies the attribute of each magnetic disk constituting the logical volume and responds to the host device as an attribute of the logical volume. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a storage device control method and a switch, and more particularly to a switch for connecting a plurality of higher-level devices (computers accessing a magnetic disk, such as a server) to a plurality of magnetic disks, and more particularly, to a switch configured from a plurality of magnetic disks. The present invention relates to a storage device control method and a switch suitable for use in a switch that performs a command control of a SCSI (Small Computer System Interface) protocol for a logical volume.
[0002]
[Prior art]
In recent years, when many magnetic disks are connected to many host devices, a connection switch is generally used. There is a fiber channel protocol as a transmission path protocol for the connection, and a fiber channel switch performs switching according to the fiber channel protocol. The fiber channel switch has an I / F for connecting to a host device and a magnetic disk, and performs data conversion. In addition, as a protocol carried by the fiber channel protocol, for example, there is a SCSI protocol. In such a protocol, a magnetic disk is identified by a set of a WWN (World Wide Name) and a LUN (Logical Unit Number).
[0003]
By the way, as described in Patent Document 1, it has been proposed that the fiber channel switch has a function of configuring a plurality of logical volumes from a plurality of magnetic disks. This fiber channel switch has a configuration information management / access right management unit and a configuration information table for managing which logical volume address range of a certain logical volume corresponds to which magnetic disk address range of which magnetic disk. I have. Then, in response to a data request from the host device, the logical volume number and the logical volume address of the logical volume are converted into the magnetic disk number and the magnetic disk address of the magnetic disk, and the data is transmitted. Here, each of the magnetic disk number and the logical volume number is an identifier for identifying itself, and is, for example, a set of the above-mentioned WWN and LUN.
[0004]
[Patent Document 1]
JP 2001-325207 A
[Problems to be solved by the invention]
Normally, in a system in which a host device and a magnetic disk are directly connected without using a switch, the host device acquires a magnetic disk information list by issuing a magnetic disk information list acquisition command to the magnetic disk. I do.
[0006]
Here, the magnetic disk information list acquisition command is a command for obtaining a magnetic disk information list, and in the SCSI protocol, includes an inquiry command and a mode sense command. Further, the magnetic disk information list is a collection of magnetic disk information, and the magnetic disk information is information unique to the magnetic disk, and includes functions unique to the magnetic disk (hereinafter, “magnetic disk function”). This includes the presence or absence of support and the parameters of the magnetic disk function. The magnetic disk function includes, for example, a tagged command queuing function that supports efficient access to the magnetic disk. By issuing a magnetic disk information list obtaining command, the host device obtains the presence or absence of such a magnetic disk function and the parameters, thereby helping to improve the efficiency of accessing the magnetic disk.
[0007]
On the other hand, in a system in which a higher-level device and a magnetic disk are connected via a switch as in the above-described related art, when the switch constitutes a logical volume from a plurality of magnetic disks, the higher-level device accesses the switch. Since the target is a logical volume, it is necessary to acquire information as a logical volume.
[0008]
Also at this time, it is necessary to return only one piece of information as a logical volume to the host device as in the case where the magnetic disk information list acquisition command is issued. If the models of the multiple magnetic disks that make up the logical volume are all the same, issue the magnetic disk information list acquisition command issued from the higher-level device to one of the multiple magnetic disks that make up the logical volume. However, there is no particular problem in the method of returning the result to the host device.
[0009]
However, it is conceivable that a plurality of magnetic disks constituting a logical volume also have different magnetic disk functions. In this case, as in the above method, a magnetic disk information list acquisition command is issued to one of the plurality of magnetic disks, and as a result, the obtained magnetic disk is returned to the higher-level device. When the magnetic disk device is accessed, mismatching may occur because the magnetic disk information does not match.
[0010]
Further, even if a magnetic disk information list acquisition command is issued to all of the respective magnetic disks and a plurality of magnetic disk information is obtained, the host device requests only one magnetic disk information. All cannot be returned to the host device.
[0011]
Therefore, it is necessary to appropriately integrate the results obtained by the magnetic disk information list acquisition command issued for each of the plurality of magnetic disks and return the result to the host device.
[0012]
When one logical disk is configured from a plurality of magnetic disks as in the above-described related art, it is necessary to return an appropriate response to a command requesting a magnetic disk information list from a higher-level device. , Has not been considered for that.
[0013]
Some software operating on the host device determines whether or not the connected magnetic disk has been verified based on information unique to the magnetic disk. Therefore, if a logical volume does not have logical volume-specific information associated with magnetic disk-specific information, such software cannot confirm whether the logical disk has been verified.
[0014]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a switch having a function of configuring a plurality of logical volumes from a plurality of magnetic disks with an attribute of a logical volume from a host device. It is an object of the present invention to provide a switch and a storage device control method that can appropriately respond to the inquiry of the above and can respond to the logical configuration and the inquiry without contradiction.
[0015]
[Means for Solving the Problems]
The present invention includes a switch that allows one or more magnetic disk devices to be logically accessed from a higher-level device and accessed as a logical volume. Then, the host inquires the attribute of the virtual storage device to the switch, and in response to the inquiry from the host, the switch inquires the attribute of the magnetic disk device constituting the logical volume. Then, in response to a response from the magnetic disk device, the switch integrates the returned attribute for each attribute of the magnetic disk device by operation or by using a fixed value and returns the integrated attribute to the host device. When inquiring or replying to attributes, for example, the SCSI protocol is used.
[0016]
In addition, information specific to a logical volume associated with information specific to a magnetic disk is returned to software operating on a higher-level device that requires information specific to a magnetic disk.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0018]
In this embodiment, a case is considered in which a physical storage device is a magnetic disk, a virtual storage device is a logical volume, and a magnetic disk is logically accessed from a host device as a logical volume for access. Then, the attribute of the physical storage device is “magnetic disk information”, and the attribute of the virtual storage device is “logical volume information”.
[0019]
First, the configuration of the storage device control system of the present invention will be described with reference to FIG.
FIG. 1 is a configuration diagram of a storage device control system of the present invention.
[0020]
The storage device control system of the present invention has a configuration in which the host device 110 and the magnetic disks 130, 140,... The higher-level device 110, the magnetic disk 130, and the switch can communicate with each other, for example, using a fiber channel protocol.
[0021]
Are logically configured as logical volumes 150, 160,..., And can access stored data via the switch 120. The logical volume may be composed of one magnetic disk, or may be composed of a plurality of magnetic disks. Further, a part of the plurality of magnetic disks may be configured as a logical volume.
[0022]
The switch 120 has a function of logically connecting a plurality of magnetic disks to the upper-level device 110 and accessing the logical disks as a logical volume, in addition to a switching function of normal communication.
[0023]
The switch 120 includes a logical volume configuration information management unit 121, a logical volume configuration information management table 122, a magnetic disk information list response unit 123, a magnetic disk information integration unit table 124, and a path switching unit 125. .
[0024]
The logical volume configuration information management unit 121 is a part that manages a magnetic disk and a logical volume in association with each other.
[0025]
More specifically, the logical volume configuration information management unit 121 assigns a logical volume number 301 and a logical volume number 301 to configure a plurality of logical volumes 150, 160 designated by the user from a plurality of magnetic disks 130, 140 designated by the user. The magnetic disk number 303 and the magnetic disk address range 304 corresponding to the volume address range 302 are registered in the logical volume configuration information management table 122.
[0026]
The logical volume configuration information management table 122 is a table in which information on a logical volume and information on a magnetic disk are stored in association with each other.
[0027]
The magnetic disk information response unit 123 is a part that inquires the magnetic disk about attribute information and receives the response.
[0028]
The magnetic disk information integration means table 124 is a table in which information on the magnetic disk is integrated and a calculation method for each attribute used when returning the attribute of the logical volume and a fixed value for a response are stored.
[0029]
The path switching unit 125 is a part that switches paths between the host device 110 and the magnetic disks 130, 140,...
[0030]
Next, a schematic procedure of the storage device control method of the present invention will be described with reference to FIG.
FIG. 2 is a diagram showing a schematic procedure of the storage device control method of the present invention.
[0031]
The host device 110 is connected to physical storage devices (magnetic disks) 130 and 140 via a switch 620. The switch 620 forms a virtual storage device (logical volume) 150 from the physical storage devices 130 and 140 and can be accessed from the host device 110.
[0032]
At this time, the higher-level device 110 can read and store data by being aware of the interface of only the virtual storage device 150 without being aware of the lower-level physical storage devices 130 and 140 at all. Therefore, by using such a switch 620, the host device 110 having the same interface as the conventional one can be used by connecting to a plurality of physical storage devices without modification.
[0033]
The higher-level device requests the attribute of the virtual storage device 150 from the switch (S661), and the switch issues a request for the attribute of the physical storage device 130 and the attribute of the physical storage device 140 (S662), and changes the attribute of the physical storage device. It is acquired (S663).
[0034]
The switch integrates the attributes in consideration of the properties of the individual attributes (S664), and returns the integrated attributes to the host device (S665).
[0035]
Hereinafter, the procedure of the storage device control method will be described in more detail.
[0036]
First, a data structure used in the present invention will be described with reference to FIGS.
FIG. 3 is a schematic diagram showing the logical volume configuration information management table 122.
[0037]
The logical volume configuration information management table 122 is a table for associating a logical volume with a configuration of a magnetic disk. The logical volume configuration information management table 122 includes a magnetic disk number 303 and a magnetic disk address range 304 corresponding to a logical volume number 301 and a logical volume address range 302. Have.
FIG. 4 is a schematic diagram showing an example of a magnetic disk information list.
[0038]
The magnetic disk information list is a list of information possessed by the magnetic disk, and FIG. 4 shows examples of the number of queuable items, the presence or absence of function support, the vendor name, the magnetic disk size, and the like.
[0039]
The queueable number is a number indicating how much a command can be queued by the magnetic disk. Whether or not a function is supported indicates whether or not a certain function is supported. The vendor name is the name of the vendor of the magnetic disk. The magnetic disk size indicates the storage capacity that can be stored.
FIG. 5 is a schematic diagram showing a magnetic disk information integration means table.
[0040]
The magnetic disk information integration means table 124 is a table for storing an arithmetic method and a fixed value used when integrating the magnetic disk information as an attribute of a logical volume, and stores the magnetic disk information stored in the magnetic disk information 511. When the name matches the magnetic disk information 501, an operation is performed on the magnetic disk information or a fixed value is returned based on the information described in the magnetic disk integration method 512.
[0041]
Next, a process in which the magnetic disk information list response unit 123 responds to the inquiry about the attribute of the logical volume of the higher-level device 110 will be described with reference to FIG.
FIG. 6 is a flowchart showing a process in which the magnetic disk information list response unit 123 responds to the inquiry about the attribute of the logical volume of the higher-level device 110.
[0042]
The magnetic disk information list response unit 123 receives a command requesting magnetic disk information for the logical volume, and extracts the logical volume number of the transmission destination recorded in the frame of the command (S401).
[0043]
Next, the magnetic disk number corresponding to the logical volume is extracted from the logical volume configuration information management table 122 (S402). Then, a command for requesting magnetic disk information is issued to the magnetic disk (S403).
[0044]
Next, it is determined that a command requesting magnetic disk information has been issued to all magnetic disks constituting the logical volume (S404).
[0045]
If a command for requesting magnetic disk information has been issued to all magnetic disks, the process proceeds to S405, and if there is a magnetic disk for which no command has been issued, the process returns to S403.
[0046]
Then, all the magnetic disk information is extracted from the magnetic disk information list obtained from the plurality of magnetic disks (S405), and from the magnetic disk information integrating means table 124, the magnetic disk information integrating means 512 corresponding to the magnetic disk information 511 is obtained. Is taken out and the magnetic disk information is integrated (S406).
[0047]
For example, in the example of "with function support" in the magnetic disk information 2, when one logical volume is composed of two magnetic disks, one of the magnetic disks supports a magnetic disk function and the other magnetic disk functions. If the magnetic disk does not support the magnetic disk function, the logical volume does not support the magnetic disk function in response to the magnetic disk information list acquisition command issued by the host device to the logical volume. Need to respond. For this purpose, a logical product operation is performed with reference to the magnetic disk integration method 512.
[0048]
Examples of the function of the magnetic disk include a failure log holding function and a device level copy function.
[0049]
In the example of the "standard version" of the magnetic disk information 4, for example, in the case of the SCSI standard version, the numbers 1 and 2 are associated with SCSI-1 and SCSI-2, respectively. In this case, for example, when a logical volume is composed of a magnetic disk supporting the SCSI-1 standard and a magnetic disk supporting the SCSI-2 standard, the lowest standard SCSI-1 is supported. Must be communicated to the host device, and the number 1 is returned to the host device.
[0050]
At this time, there is a case where the upper standard does not necessarily support the function of the lowest standard. In this case, among the target “standard versions”, the version of the common standard is used as the attribute of the logical volume as Be responsive.
[0051]
As another example, when the vendor name of the magnetic disk information 3 is inquired, a character string unique to the logical volume is returned.
[0052]
Further, when there is an inquiry about the magnetic disk size of the magnetic disk information n, the total value of the sizes of the magnetic disks constituting the logical volume is returned.
[0053]
In addition, for software that is not shown in FIG. 4 but runs on a higher-level device that requires information unique to the magnetic disk, information unique to the logical volume associated with information unique to the magnetic disk may be returned. Just fine.
[0054]
Finally, the integrated magnetic disk information list is transmitted to the host device 110 (S407).
[0055]
In the present embodiment, the magnetic disk information is integrated using the magnetic disk information integrating means table 124. However, in addition to this method, in step S406, multiple branch processing is performed for each magnetic disk information. It is also possible to perform a unique integration process on the magnetic disk information of the magnetic disk. In that case, the magnetic disk information integration means table 124 becomes unnecessary.
[0056]
In the present embodiment, the magnetic disk information list is acquired from the magnetic disk in response to a command requesting the magnetic disk information list from the host device 110. However, before this timing, the magnetic disk information list is acquired from the magnetic disk. It is also possible to obtain a list and integrate the magnetic disk information list. If this method is adopted, the integrated magnetic disk information list can be returned at a higher speed in response to the magnetic disk information list request from the host device. When this method is adopted, the trigger for acquiring and integrating the magnetic disk information list from the magnetic disk is when the magnetic disk is connected to the switch. The trigger for updating the previously integrated magnetic disk information list is when a magnetic disk device is newly connected and when configuration information is changed.
[0057]
Further, in this embodiment, the path switching unit, the logical volume configuration information management unit, and the magnetic disk information response unit coexist in the switch, but they are separated into separate devices and connected by a communication path such as a fiber channel. Then, an embodiment for realizing the present invention is also conceivable.
[0058]
As described above, by operating the magnetic disk information list response unit 123 of the switch 120, a magnetic disk information list issued to a logical volume composed of a plurality of magnetic disks supporting different magnetic disk information is obtained. Since an appropriate response can be returned to the command, the higher-level device can efficiently access the logical volume.
[0059]
In the present embodiment, the switch 120 has been described as an example of a device that configures a magnetic disk that is a physical storage device from a logical volume that is a logical storage device. The present invention can also be applied to a device placed between the storage device. For example, a computer may be placed between the host device 110 and the magnetic disk, and the computer may virtualize the magnetic disk and make it look like a logical volume.
[0060]
In the present embodiment, a magnetic disk has been described as an example of a physical storage device. However, the present invention can be applied to a storage device that stores data in another storage medium, such as a magnetic tape, a semiconductor storage device, and an optical disk. .
[0061]
【The invention's effect】
According to the present invention, a switch having a function of configuring a plurality of logical volumes from a plurality of magnetic disks is appropriately responded to an inquiry about the attribute of a logical volume from a higher-level device, and the logical configuration and the inquiry are made. , And a storage device control method can be provided.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a storage device control system of the present invention.
FIG. 2 is a diagram showing a schematic procedure of a storage device control method of the present invention.
FIG. 3 is a schematic diagram showing a logical volume configuration information management table 122;
FIG. 4 is a schematic diagram showing an example of a magnetic disk information list.
FIG. 5 is a schematic diagram showing a magnetic disk information integration means table.
FIG. 6 is a flowchart showing a process in which the magnetic disk information list response unit 123 responds to an inquiry about the attribute of the logical volume of the host device 110.
[Explanation of symbols]
110: host device, 120: switch, 130, 140: magnetic disk, 150, 160: logical volume, 121: logical volume configuration information management section, 122: logical volume configuration information management table, 123: magnetic disk information list response section, 124: magnetic disk information integration means table; 125: path switching unit.

Claims (9)

In a storage device control method for logically connecting one or more physical storage devices and accessing the virtual storage device from a higher-level device,
Querying the attribute of the virtual storage device from the higher-level device;
In response to an inquiry from the higher-level device, a procedure for inquiring about attributes of physical storage devices constituting the virtual storage device,
For responding to the response from the physical storage device, integrating the returned attributes into attributes of the virtual storage device;
Responding to the inquiry about the attribute of the virtual storage device from the higher-level device. The method according to claim 1, wherein in the step of integrating the returned attributes, the attributes to be integrated are obtained by performing an operation based on the characteristics of each attribute, or are fixed values based on each attribute. 2. The storage device control method according to claim 1. 2. The storage device control method according to claim 1, wherein a procedure for inquiring an attribute of the virtual storage device from the higher-level device and a procedure for responding are performed by a SCSI protocol. In a switch that connects a higher-level device and one or more physical storage devices, and logically accesses the physical storage device and makes it accessible as a virtual storage device,
In response to an inquiry about the attribute of the virtual storage device from the higher-level device, an inquiry is made about the attribute of the physical storage device constituting the virtual storage device, and the attributes returned from the physical storage device are integrated to integrate the attributes of the virtual storage device. A switch comprising: responding to a query with an attribute of the virtual storage device from the host device as an attribute. 5. The switch has operation information or a fixed value for each attribute of the physical storage device, and uses the operation information or the fixed value as an attribute of the integrated virtual storage device. 6. The described switch. 5. The switch according to claim 4, wherein the host device inquires about the attribute of the virtual storage device and replies the SCSI device according to the SCSI protocol. In a storage device control system in which one or more physical storage devices are logically accessed from a higher-level device and accessed as a virtual storage device,
This system is
A host device,
One or more physical storage devices;
A switch that connects the physical storage device and the higher-level device, logically logicalizes the physical storage device, and accesses the virtual storage device,
The higher-level device queries the switch for an attribute of the virtual storage device,
The switch inquires of an attribute of a physical storage device constituting the virtual storage device in response to an inquiry from the higher-level device, and in response to a response from the physical storage device, integrates the returned attributes and integrates the returned attribute. A storage device control system, wherein an attribute of the virtual storage device from the higher-level device is responded to an inquiry as an attribute of the virtual storage device. 8. The switch according to claim 7, wherein the switch has operation information or a fixed value for each attribute of the physical storage device, and the operation information or the fixed value is used as an attribute of the integrated virtual storage device. The storage device control system according to claim 1. 8. The storage device control system according to claim 7, wherein said switch has a function of performing switching by a fiber channel protocol.

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