JP2008016063A - Input-output control equipment, input-output control method, and storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide input-output control equipment, an input-output control method, and a storage system which can perform hot swap of a device connected to the input-output control equipment, in relating to the input-output control equipment, the input-output control method, and the storage system which makes possible hot swap of a device which controls an access based on a reference logical unit number which serves as a reference among logical unit numbers. <P>SOLUTION: In the input-output control equipment which controls the access based on the reference logical unit number which serves as the reference among the logical unit numbers, it is characterized by having a detecting means which detects the access to the device of the reference logical unit number when the device of the reference logical unit number cannot operate normally or is not connected, and a response means for performing a predetermined response instead of the device of the reference logical unit number when the access to the device of the reference logical unit number is detected by the detecting means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an input / output control apparatus, an input / output control method, and a storage system, and more particularly to an input / output capable of hot removal of a device that controls access based on a reference logical unit number as a reference among logical unit numbers The present invention relates to a control device, an input / output control method, and a storage system.

  In recent years, fiber channel has attracted attention as the next generation interface of SCSI (Small Computer System Interface).

  The storage system has a large capacity that can be stored in a single unit. As the capacity of a storage system increases, a function that can be used from a plurality of servers is required.

  As the interface, a fiber channel capable of transferring data at high speed is becoming widespread. At this time, it is required to be able to share the SCSI interface and the fiber channel.

  A conventional SCSI interface uses a device type and a serial number to manage devices.

  On the other hand, the fiber channel is required to be managed by WWN (world wide name) according to the standard. The WWN must be set to a unique value for each connection port with a data length of 8 bytes. For this reason, the device type and serial number used in the conventional SCSI interface are not unique values for each connection port. Therefore, it is necessary to set a new WWN.

  In the SCSI interface, a target ID and a logical unit number are designated at the time of access. On the other hand, according to the standard, only the logical unit number is specified for Fiber Channel. That is, in the fiber channel, it is necessary to give each storage apparatus a different logical unit number.

  Further, in the SCSI interface, the logical unit number LUN is defined as an essential device according to the standard. For this reason, when a device whose logical unit number LUN is 0 is replaced, all devices cannot be used.

  The present invention has been invented to solve the above problems, and is solved by the following invention.

  The present invention provides an input / output control apparatus that controls access based on a reference logical unit number as a reference among logical unit numbers, when the device of the reference logical unit number cannot operate normally or is not connected. Detecting means for detecting access to the device having the reference logical unit number, and when the access to the device having the reference logical unit number is detected by the detecting means, a predetermined value is substituted for the device having the reference logical unit number. Response means for making a response is provided.

  Further, the present invention provides an input / output control method for controlling access to a device based on a reference logical unit number serving as a reference among logical unit numbers, wherein the device of the reference logical unit number cannot operate normally or is connected If access to the device having the reference logical unit number is detected when not done, a predetermined response is made instead of the device having the reference logical unit number.

  Furthermore, the present invention is a storage system comprising: a storage device; and an input / output control device connected to the storage device via a first interface and connecting the first interface and the second interface. The input / output control device includes: a detection unit that detects access to the device of the reference logical unit number when the device of the reference logical unit number cannot operate normally or is not connected; and the detection unit When access to the device having the reference logical unit number is detected, response means is provided for performing a predetermined response in place of the device having the reference logical unit number.

  According to the present invention, when access to the device of the reference logical unit number is detected when the device of the reference logical unit number cannot operate normally or is not connected, the device of the reference logical unit number is replaced. By performing a predetermined response, it is possible to perform hot insertion / removal of a device connected to the input / output control device.

FIG. 1 shows a block diagram of an embodiment of the present invention.
The system 1 according to the present embodiment has a configuration in which host computers 2-1 and 2-2 and storage systems 3-1 to 3 -n are connected by an interface 4.

  The host computers 2-1 to 2-2 share the storage systems 3-1 to 3-n. The storage systems 3-1 to 3-n are composed of a storage device 11 and a channel adapter 12. A plurality of storage apparatuses 11 and channel adapters 12 may be provided in the storage systems 3-1 to 3-n.

The storage device 11 is composed of, for example, a hard disk drive and stores data. The channel adapter 12 is connected between the interface 4 and the storage device 11 and connects the storage device 11 to the interface 4.
The interface 4 is composed of a fiber channel. The fiber channel is a high-speed serial interface, and a device is recognized by a WWN (World Wide Name).

  Next, the channel adapter 12 of this embodiment will be described in detail.

  FIG. 2 is a configuration diagram of a connection portion of a channel adapter according to an embodiment of the present invention. In the figure, reference numeral 21 denotes an interface board of the host computer 2-1. A plurality of SCSI ports 22-1 to 22-m, a ROM 23, a controller 24, and the like are mounted on the interface board 21. Port numbers are set in advance for the plurality of SCSI ports 22-1 to 22-m. The port number is stored in the ROM 23 mounted on the interface board 21 and is read from the ROM 23 by the controller 24.

  The channel adapter 12 is connected to one SCSI port 22-i among the plurality of SCSI ports 22-1 to 22-m. When the power is turned on, the channel adapter 12 requests the port number of the SCSI port 22-i from the interface board 21. The request is supplied to the controller 24 of the interface board 21. The controller 24 reads the port number corresponding to the SCSI port 22-i from the ROM 23 and supplies it to the channel adapter 12.

The channel adapter 12 stores a device type, a company ID, and a serial number, and creates a WWN together with a port number from the SCSI port 22-i.
Next, the channel adapter 12 will be described in detail.

FIG. 3 is a block diagram of a channel adapter according to an embodiment of the present invention.
The channel adapter 12 includes control logic units 31 and 32, a driver 33, an MPU 34, a memory 35, an MPU bus 36, a data buffer 37, a fiber channel processor 38, and a transmission / reception circuit 39.

The control logic unit 31 controls communication with the storage device 11. The control logic unit 32 controls writing and reading of data to and from the data buffer 37.
The driver 33 performs transmission / reception with the RS-232C. RS-232C is used as a debugger interface.

  The MPU 34 performs processing such as creation of a WWN. The memory 35 includes a ROM 41 and a RAM 42. The ROM 41 stores a program for creating a WWN, a device type, a company ID, a model ID, and a serial number. The RAM 42 is used as a working storage area for the MPU 34.

  The MPU bus 36 connects the control logic units 31 and 32, the MPU 34, and the memory 35. The data buffer 37 temporarily stores data from the storage device 11 and data from the fiber channel 4.

  The fiber channel processor 38 performs data conversion. The transmission / reception circuit 39 receives data from the fiber channel 4 and transmits data to the fiber channel 4.

  Next, the WWN creation processing operation of the MPU 34 will be described in detail.

FIG. 4 shows a process flowchart of the WWN creation process according to an embodiment of the present invention.
The WWN creation process includes steps S1-1 to S1-7.
Step S1-1 is a step of determining whether or not the channel adapter 12 is powered on. When the channel adapter 12 is turned on in step S1-1, step S1-2 is executed.

  Step S1-2 is a process of reading the device type, company ID, model ID, and serial number from the ROM 41 and setting them in the RAM 42. When the device type, company ID, model ID, and serial number are set in the RAM 42, next, step S1-3 is executed.

  Step S1-3 is a step of determining whether or not a fiber channel is set as an interface. If the fiber channel is set as the interface to be used in step S1-3, then step S1-4 is executed.

  Step S1-4 is a step of creating a WWN. The creation of the WWN in step S1-4 will be described in detail later. When the WWN is created in step S1-4, next step S1-5 is executed. In step S1-5, it is determined whether or not to enable the WWN created in step S1-4.

If it is set in step S1-5 to enable WWN, WWN is enabled in step S1-6. If it is set in step S1-5 to disable WWN, WWN is disabled in step S1-7.
As described above, the WWN is set in the channel adapter 12, and the communication by the fiber channel becomes possible.

  Next, the creation of the WWN in step S1-4 will be described in detail.

FIG. 5 is a process flowchart of a WWN creation process according to an embodiment of the present invention.
Step S1-4 includes steps S2-1 to S2-4.

  Step S2-1 is a step of requesting a port number from the connected SCSI port 22-i. When a port number is requested in step S2-1, step S2-2 is executed. Step S2-2 is a step of determining whether or not the port number of the SCSI port 22-i has been acquired.

  When the port number of the SCSI port 22-i is acquired in step S2-2, next, step S2-3 is executed.

  Step S2-3 is a step of reading the device type, company ID, model ID, and serial number from the RAM. If the device type, company ID, model ID, and serial number are read from the RAM 42 in step S2-3, then step S2-4 is executed.

  Step S2-4 is a step of creating a WWN by combining the port number, device type, company ID, model ID, and serial number.

  Here, the operation of the controller 24 of the interface board 21 will be described.

FIG. 6 shows a process flowchart of the controller of one embodiment of the present invention.
The controller 24 of the interface board 21 executes steps S3-1 to S3-3 in response to a request from the channel adapter 12.
Step S 3-1 is a step of determining whether or not a request for a port number has been received from the channel adapter 12. When a port number request is received from the channel adapter 12 in step S3-1, step S3-2 is executed.

  In step S3-2, the port number of the requested SCSI port 22-i is read from the ROM 41. When the port number is read in step S3-2, next step S3-3 is executed.

Step S3-3 is a step of sending the port number read in step S3-2 to the requested SCSI port 22-i.
As described above, the port number corresponding to the SCSI port 22-i to which the channel adapter 12 is attached is supplied to the channel adapter 12.

  Next, the configuration of the WWN created in FIG. 5 will be described in detail.

  FIG. 7 is a data configuration diagram of the WWN according to an embodiment of the present invention.

  The WWN is 8 bytes and 64 bits long according to the ANSI (American National Standard Institute) standard.

  As shown in FIG. 7, the port number read from the interface board 21 corresponding to the SCSI port 22-i is set in 59 to 56 bits. The device type read from the ROM 41 is set in the 55 to 48 bits. The company ID is set in the 47th to 24th bits. In 23 to 16 bits, a model ID is set. In the 15 to 0 bits, a manufacturing serial ID is set. Note that 63 to 60 bits are fixed values.

  As described above, the WWN is automatically created. Therefore, the WWN is not set by mistake. Furthermore, the device type, company ID, model ID, and manufacturing serial ID are also set in the existing device. Therefore, it is not necessary to newly assign WWN.

  Next, a method for sharing a storage apparatus between SCSI and Fiber Channel will be described.

  In this embodiment, in order to share the storage device between SCSI and Fiber Channel, it is assumed that the Fiber Channel logical unit number FCLUN indicated by Fiber Channel is combined with the target ID and SCSI logical unit number SCSILUN.

  FIG. 8 is a diagram for explaining the relationship between the fiber channel logical unit number and the SCSI logical unit number in one embodiment of the present invention. 8A shows the data structure of the target ID, FIG. 8B shows the SCSI logical unit number SCSILUN, and FIG. 8C shows the data structure of the fiber channel logical unit number FCLUN.

  The channel adapter 12 manages the target ID shown in FIG. 8A and the SCSI logical unit number SCSILUN shown in FIG. When a fiber channel is used as an interface, the target ID shown in FIG. 8A and the SCSI logical unit number SCSILUN shown in FIG. 8B are combined, and 1 byte as shown in FIG. 8C. A Fiber Channel logical unit number FCLUN is created. The fiber channel logical unit number FCLUN shown in FIG. 8C has a different value for all logical units.

As described above, the Fiber Channel LUN is configured by combining the target ID and the SCSI LUN, so that the same target ID is given when it is desired to show the same area as the SCSI and when the same area is accessed by a plurality of ports. In the case of fiber channel independent setting, it can be controlled by giving a dummy target ID.
Next, a method for preventing all devices from being recognized when there is no device with the logical unit number LUN = 0 will be described.
In this embodiment, the pseudo LUN0 mode is set in the channel adapter 12 in order to prevent all devices from being recognized when there is no device with the logical unit number LUN = 0.
First, the pseudo LUN0 mode setting operation will be described.

  FIG. 9 shows a flowchart when setting the pseudo LUN0 mode of the channel adapter according to the embodiment of the present invention.

The pseudo LUN0 mode setting process includes steps S5-1 to S5-2.
Step S5-1 is a step of determining whether or not the pseudo LUN0 mode is set by the maintenance manager.
When the pseudo LUN0 mode is set by the maintenance manager in step S5-1, the channel adapter 12 is set in the pseudo LUN0 mode in step S5-2.
In step S5-1, if the pseudo LUN0 mode is not set by the maintenance manager, a normal response is made.
At this time, the maintenance manager can cope with the failure of the device in which the pseudo LUN0 mode is set even when the device with the logical unit number LUN is 0.
Next, the pseudo LUN0 mode process will be described in detail.

FIG. 10 shows a processing flowchart of the pseudo LUN0 mode of the channel adapter according to the embodiment of the present invention.
The pseudo LUN0 mode process includes steps S6-1 to S6-9.
Step S6-1 is a step of determining whether or not an access has been made to a device whose logical unit number LUN is 0. If it is determined in step S6-1 that the access is to a device other than the device with the logical unit number LUN0, the processing ends.

If it is determined in step S6-1 that the access is to the device having the logical unit number LUN0, then step S6-2 is executed. Step S6-2 is a step of determining whether or not the pseudo LUN0 mode is set.
If the pseudo LUN0 mode is not set in step S6-2, no processing is performed. If the pseudo LUN0 mode is set in step S6-2, next, step S6-3 is executed.

Step S6-3 is a step of determining whether or not the command requested to the channel adapter 12 is a request command (inquiry command). If it is determined in step S6-3 that the command is a request command, step S6-4 is executed.
Step S6-4 is a step for making a normal response. In step S6-3, only standard data request (Standard inquiry data) is supported as a request command, and information indicating that a logical unit number is configured as a peripheral qualifier as a response. respond.

  If it is determined in step S6-3 that the command is not a request command, step S6-5 is executed. Step S6-5 is a step of determining whether or not the command is a read capacity command.

  When a read capacity command is received in step S6-5, step S6-6 is executed. Step S6-6 is a step of returning a response in which the logical block address is 0 and the block length is “0x200”. The response block length “0x200” is the data length of data that would normally be transferred when a device exists. If it is determined in step S6-5 that the command is not a capacity command, step S6-7 is executed next.

  Step S6-7 is a step of determining whether or not the command is a mode sense command.

  When a mode sense command is received in step S6-7, step S6-8 is executed. In step S6-8, the number of data blocks is 0, the block length is a preset block length, the number of sectors / tracks is 0, the number of cylinders is 0, and the values set when other areas are normally transferred Is a step of making a response using as a data.

  If it is another command at step S6-7, step S6-9 is executed. Step S6-9 is a step of responding with a preset check condition.

  It should be noted that even if there is another device whose logical unit number LUN is 0 or whose fiber channel address is 0, a mode is set in which the logical unit number LUN or fiber channel address of the device to be actively removed is set to 0.

At this time, when an access is made to a device that has a logical unit number LUN of 0 or a fiber channel address of 0, normal processing is performed on this device. To do.
As described above, according to the present embodiment, it is also possible to access on the fiber channel by using an identifier for accessing on the SCSI interface.

Also, since the WWN can be set with a fixed port, the same WWN can be reproduced even if the adapter port is replaced, and it is not recognized as a separate device even after conversion on the interface, that is, on the network. Therefore, it becomes possible to activate. Further, it is not necessary to change the setting on the host computer side during maintenance work.
As described above, the active removal of the device becomes possible.

  In addition, this invention is not limited to the said Example, It cannot be overemphasized that a various modified example can be considered in the range which does not deviate from the summary of this invention.

It is a block block diagram of one Example of this invention. It is a block diagram of the connection part of the channel adapter of one Example of this invention. It is a block block diagram of the channel adapter of one Example of this invention. It is a process flowchart of the WWN creation process of one Example of this invention. It is a process flowchart of the creation process of WWN of one Example of this invention. It is a process flowchart of the controller of one Example of this invention. It is a data block diagram of WWN of one Example of this invention. It is a figure for demonstrating the relationship between the fiber channel logical unit number of 1 Example of this invention, and a SCSI logical unit number. It is a flowchart at the time of pseudo LUN0 mode setting of the channel adapter of one Example of this invention. It is a process flowchart of the pseudo LUN0 mode of the channel adapter of one Example of this invention.

Explanation of symbols

1 system 2-1, 2-2-2 host computer 3-1-3 -n storage system, 4 interface 11 storage device, 12 channel adapter 21 interface board, 22-1-22 -m SCSI port 23 ROM, 24 controller 31, 32 Control logic part, 33 Driver, 34 MPU, 35 Memory 36 MPU bus, 37 Data buffer, 38 Fiber channel processor 39 Transmission / reception circuit 41 ROM, 42 RAM

Claims (3)

In an input / output control device that controls access based on a reference logical unit number as a reference among logical unit numbers,
Detecting means for detecting access to the device of the reference logical unit number when the device of the reference logical unit number cannot operate normally or is not connected;
An input / output control device comprising: response means for performing a predetermined response in place of the device of the reference logical unit number when the access to the device of the reference logical unit number is detected by the detection means. In an input / output control method for controlling access to a device based on a reference logical unit number as a reference among logical unit numbers,
When access to the device of the reference logical unit number is detected when the device of the reference logical unit number cannot operate normally or is not connected, a predetermined value is used instead of the device of the reference logical unit number. An input / output control method for responding. A storage system comprising: a storage device; and an input / output control device connected to the storage device via a first interface and connecting the first interface and the second interface,
The input / output control device includes:
Detecting means for detecting access to the device of the reference logical unit number when the device of the reference logical unit number cannot operate normally or is not connected;
A storage system comprising response means for performing a predetermined response in place of the device of the reference logical unit number when access to the device of the reference logical unit number is detected by the detection means.

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