JP2007241845A - Fc-al switch, master port decision method for it, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a selection time in selection of a master port of a loop from a plurality of devices constituting the loop in an FC-AL system. <P>SOLUTION: This FC-AL switch 201 connects a plurality of devices in a loop as a plurality of ports constituting an FC-AL loop. The FC-AL switch 201 is provided with a loop configuration storage part 301 holding a loop configuration history, which specifies a port of the loop and a device connected to the port, and a port name of a device selected as a master port for deciding an address of each device connected to the loop, and a control part 302 selecting the master port of the loop configured in the previous time as the master port for the loop to be configured this time based on the loop configuration history and the master port in the loop configuration storage part 301 when the loop is initialized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an FC-AL switch, a master port determination method thereof, and a program, and more particularly to a method of shortening a determination time when determining an FC-AL master port.

  Conventional FC-AL (Fibre Channel-Arbitrated) will be described with reference to FIG.

  As shown in FIG. 4, the transmission line 402 of the device A101 is connected to the reception line 501 of the adjacent device B102, the transmission line 502 of the device B102 is connected to the reception line 601 of the device C103, and the transmission line 602 of the device C103 is connected to the device D104. A form in which all the devices A101 to D104 are connected to the receiving line 701, the transmission line 702 of the device D104 to the receiving line 401 of the device A101, etc., and connected in a loop is called AL (Arbitrated Loop).

  As described above, since all devices A101 to D104 connected to the FC-AL switch 201 exist on one loop, an address is assigned to each device. Next, this address determination sequence will be described.

  In FIG. 4, the devices A 101 to D 104 are connected to the FC-AL switch 201. Each device A101-D104 sends a LIP primitive sequence to participate in the loop. LIP is an abbreviation of Loop Initialization Primitive, and is a primitive sequence for requesting loop initialization.

  Next, each of the devices A101 to D104 transmits a LISM frame in order to select a master port that leads the loop initialization. Here, the LISM frame is a Loop Initialization Select Master frame that is used to select a master port in a loop. The LISM frame format is shown in FIG. As shown in FIG. 5, a 4-byte SOF (Start Of Frame) and an EOF (End Of Frame) are arranged at the beginning and end of the LISM frame, and an 8-byte port name and a 4-byte CRC are placed between them. Inserted.

  Next, each of the devices A101 to D104 algebraically compares the byte value corresponding to the port name in the received LISM frame with the byte value corresponding to its own port name, and the byte value corresponding to the received port name. Is larger than the byte value corresponding to its own port name, the received LISM frame is discarded and the LISM frame is continuously transmitted. On the other hand, if the byte value corresponding to the received port name is smaller than the byte value corresponding to its own port name, each of the devices A101 to D104 transmits the received LISM frame instead of its own LISM frame.

  As a result of the devices A101 to D104 performing these processes, the device that has received the LISM frame having its own port name becomes the master port. The device that has become the master port transmits a primitive sequence notifying other devices that the master port has been selected. Thereafter, the master port determines the address of each device based on the determined sequence. However, the address determination sequence after determining the master port is not described in the present invention, and is a well-known technique. Omit.

  Here, the LIP primitive sequence is sent out when the initialization request from another device is recognized, when trying to join from a non-participating state in the loop, when the power is turned on, or when a loop failure is detected. For example, loop initialization also occurs when a device is reset by initial setting of the device. For this reason, even if a reset occurs in the initial setting or the like and a device that has formed a loop forms the same loop again, the loop initialization must be started from the beginning each time.

  As prior art documents related to FC-AL, Patent Document 1 discloses a Fiber Channel loop interface circuit having a dedicated transmission frame buffer for loop initialization and response, and Patent Document 2 reduces risk of hard address conflict. For this purpose, a method for determining the address of a device connected to the FC-AL has been proposed.

  In Patent Document 3, a switch-connected device acquires a unique address without requiring a special operation or procedure, and an FC-AL switch for the purpose of performing a high-speed switch operation. An address determination method has also been proposed.

  In Patent Document 4, a circuit for monitoring loop initialization processing is provided for the purpose of quickly recovering from a failure when a loop failure occurs in an FC-AL system, and state transition monitoring and loop initialization processing are provided. A loop failure recovery method for an FC arbitrated loop compatible device has been proposed in which the failure device itself bypasses the port and disconnects from the loop when a timeout is detected, and transmits a loop initialization primitive immediately before the port bypass.

  Further, in Patent Document 5, for the purpose of enabling continuous operation of the FC switch device even if a failure occurs in the switch circuit or the like, the connection between the four port control units is switched by the switch circuit, and the switching circuit or port control is performed. A failure avoidance circuit for an FC switch device has been proposed that includes a switching control unit that changes the output of the port control unit to an LIP primitive when the unit fails.

  Patent Document 6 discloses an FC-AL switch for enabling a private device connected to a predetermined port of an FC-AL specification switch to communicate with a device connected to another port. Has been proposed. In this FC-AL switch, the address of each device is determined by the address allocation unit in the address format of the private device. Data sent from the public device in the loop connected to the port to the private device is transferred to the port based on the connection information that associates each device with the port in the connection information holding unit, and is connected to the loop. Sent to a private device. Data transmitted from the private device to the public device is transferred to the port based on the connection information and transmitted to the public device connected to the loop.

Furthermore, in Patent Document 7, a switch circuit that controls connection of a device connected to the FC-AL communication path, and whether or not the device is connected to the communication path immediately before stopping the power supply for switching circuit operation are stopped. There has been proposed a device connection control circuit that includes a storage circuit that stores the connection state shown, and that controls the connection so that the switch circuit is in the connection state stored in the storage circuit when power supply is started.
JP 2001-523862 A JP 2000-332804 A JP 2001-045035 A JP 2003-158528 A Japanese Patent Laid-Open No. 2005-210166 JP 2000-259543 A JP 2005-202892 A

  As described above, in the FC-AL, a master port is selected in order to determine the address of each device connected to the loop in the loop initialization sequence. However, there are many cases where the device is reset in order to perform initial setting of the apparatus, etc., but when the initial setting of the device is performed, the loop is initialized, so even if the device connected to the loop is not changed A predetermined initialization sequence is executed each time. For this reason, the time for selecting a master port becomes longer, and a countermeasure for this is desired. The above-mentioned Patent Documents 1 to 7 are not necessarily made by recognizing such a problem.

  The present invention has been made in consideration of such a conventional situation, and in a FC-AL system in which a plurality of devices are connected in a loop, the master port of the loop is selected from a plurality of devices constituting the loop. The purpose is to shorten the selection time.

  In order to achieve the above object, an FC-AL switch according to the present invention is an FC-AL switch in which a plurality of devices are connected as a plurality of ports constituting an FC-AL loop. Holding means for holding a loop configuration history indicating a history of whether or not connected, and a port name of a device selected as a master port for determining an address of each device connected to the loop among the plurality of devices; Master port selection means for selecting the master port of the loop configured last time as the master port of the loop that is configured this time based on the loop configuration history and the master port of the holding means at the time of initialization of the loop. And

  In the present invention, the master port selecting means determines whether or not the loop configured this time and the connection state of the port are the same as those configured last time based on the loop configuration history of the holding means when the loop is initialized. When the first determination means determines that the connection state of the loop configured this time and the port thereof is the same as that previously configured by the first determination means, the holding means Notification means for notifying each device of a LISM frame sent from the master port corresponding to the port name, and a LISM frame sent from each device in response to the notification means is a LISM frame from the master port A second determination means for determining whether or not the same as the LISM file from each device by the second determination means. If the over-time is determined to be the same as the LISM frame from the master port, the master port may have a master port recognition means for recognizing a selected properly.

  In this case, the master port selecting means stores the loop configuration history of the currently configured loop and the port name of the master port in the holding means after the master port recognizing means recognizes that the master port has been selected normally. You may further have a means to preserve | save.

  The master port selection means, when the second judgment means judges that the LISM frame from each device is not the same as the LISM frame from the master port, the information held in the holding means And a means for transmitting a LIP and performing a normal initialization sequence.

  Further, the master port selection means performs a normal initialization sequence when it is determined by the first determination means that the loop configured this time and the connection state of the port are not the same as those previously configured. You may have further means to perform.

  The FC-AL system according to the present invention includes any one of the FC-AL switches described above and a plurality of devices connected to the FC-AL switch.

  The FC-AL switch master port determination method according to the present invention is the FC-AL switch master port determination method in which a plurality of devices are connected as a plurality of ports constituting an FC-AL loop. The storage unit stores a loop configuration history indicating a history of which device is connected, and a port name of a device selected as a master port for determining an address of each device connected to the loop among the plurality of devices. And a step of selecting the master port of the loop configured last time as the master port of the loop configured this time based on the loop configuration history and the master port stored in the storage unit at the time of initialization of the loop It is characterized by having.

  An FC-AL switch master port determination program according to the present invention is an FC-AL switch master port determination program for connecting a plurality of devices as a plurality of ports constituting an FC-AL loop. A loop configuration history indicating a history of which port is connected to which device, and a port name of a device selected as a master port for determining an address of each device connected to the loop among the plurality of devices. Select the master port of the previously configured loop as the master port of the loop that is currently configured based on the loop configuration history and master port stored in the storage unit at the time of loop initialization and loop initialization. And a step of performing

  According to the present invention, in an FC-AL system in which a plurality of devices are connected in a loop, the selection time for selecting a master port of the loop from a plurality of devices constituting the loop can be shortened.

  Next, the best mode for carrying out the FC-AL switch, its master port determining method and program according to the present invention will be described in detail with reference to the drawings.

  The FC-AL system according to the present embodiment shown in FIG. 1 has a device connected to each port of the FC-AL switch 201 (for example, a computer device such as a server device constituting a storage area network, a disk device, a tape device, etc.). A101, B102, C103, and D104 are connected. Each of the devices A101 to D104 has an FC-AL loop configuration of device A101 → device B102 → device C103 → device D104 → device A101. That is, each of the devices A101 to D104 connects the transmission line 402 of the device A101 to the reception line 501 of the adjacent device B102, the transmission line 502 of the device B102 to the reception line 601 of the device C103, and the transmission line 602 of the device C103. All devices A101 to D104 are connected to the receiving line 701 of the device D104, the transmission line 702 of the device D104 to the receiving line 401 of the device A101, and the like, and connected in a loop.

  In the present embodiment, the FC-AL switch 201 includes a loop configuration storage unit (which constitutes the holding means of the present invention) 301 and a control unit that operates in conjunction with the loop configuration storage unit 301 (master port selection of the present invention). 302). The loop configuration storage unit 301 stores a configuration history indicating whether or not a loop has been configured, and which device is the master port that leads the loop initialization and determines the address of each device. Specifically, as shown in FIG. 2, a loop configuration history a1 indicating to which port of the FC-AL switch 201 the loop configured last time is configured, and a master port a2 at that time Information, that is, the port name (8 bytes) of the device that has become the master port. The loop configuration storage unit 301 is configured by a recording medium such as a RAM (Random Access Memory) in the FC-AL switch 201. The control unit 302 plays a central role in controlling various operations of the FC-AL switch 201, and includes, for example, a processor (microcontroller) such as a CPU (Central Processing Unit) that operates under program control.

  Next, the operation of the FC-AL switch 201 of FIG. 1 will be described using the flowchart of FIG. In the present embodiment, the control program code shown in the flowchart of FIG. 3 is stored in a recording medium (not shown) such as a ROM or a hard disk that records the program code in the FC-AL switch 201, and the control unit is operated during operation. The instruction is read and read by a processor (CPU) constituting 302.

  First, when the FC-AL switch 201 receives a LIP primitive sequence from a certain device (step St1), the control unit 302 confirms the loop configuration history a1 in the configuration storage unit 301, and whether or not the previous loop has been configured. Is determined (step St2).

  As a result, if the previous loop is not configured (step St2: NO), the FC-AL switch 201 performs a normal initialization sequence by the control unit 302 (step St3). Here, the normal initialization sequence is a master from each port (each device) by comparing the byte value corresponding to the port name of the received LISM frame with the byte value corresponding to its own port name. Refers to the sequence of selecting ports.

  That is, in the normal initialization sequence, each of the devices A101 to D104 transmits a LIP primitive sequence in order to participate in the loop. Next, each of the devices A101 to D104 transmits a LISM frame in order to select a master port that leads the loop initialization. Next, each of the devices A101 to D104 algebraically compares the byte value corresponding to the port name in the received LISM frame with the byte value corresponding to its own port name, and the byte value corresponding to the received port name. Is larger than the byte value corresponding to its own port name, the received LISM frame is discarded and the LISM frame is continuously transmitted. On the other hand, if the byte value corresponding to the received port name is smaller than the byte value corresponding to its own port name, each of the devices A101 to D104 transmits the received LISM frame instead of its own LISM frame. As a result of the devices A101 to D104 performing these processes, the device that has received the LISM frame having its own port name becomes the master port. The device that has become the master port transmits a primitive sequence notifying other devices that the master port has been selected. When the normal initialization sequence ends, the process proceeds to step St8 described later.

  On the other hand, if it is determined in step St2 that a previous loop has been configured (step St2: YES), the FC-AL switch 201 is configured based on the loop configuration history a1 in the configuration storage unit 301. The device connection status of each port is compared with the device connection status of each port of the loop configured this time, and it is checked whether there is an increase or decrease in ports (increase or decrease in devices connected to the loop) (step St4). ). As a result, if the number of ports is increased or decreased (step St4: NO), the above-described normal initialization sequence is performed (step St3). Thereafter, the process proceeds to step St8 described later.

  On the other hand, if there is no increase / decrease in the port in the check in step St4 (step St4: YES), it is recognized that the loop to be configured this time is the same as the loop configured previously, and the configuration storage unit 301 Based on the port name a2 held in the master port a2, the device that becomes the master port of the loop configured previously is selected as the master port of the loop configured this time, and waits for the LISM frame from the master port. . This LISM frame includes the port name of the device corresponding to the master port. Therefore, in this routine, the normal initialization sequence (step St3) is omitted.

  When the FC-AL switch 201 receives the LISM frame from the master port (step St5), the FC-AL switch 201 transmits the received LISM frame to each port (each device A101 to D104) by broadcast (step St6). When each of the devices A101 to D104 receives the LISM frame transmitted by broadcast from the FC-AL switch 201, each device A101 to D104 obtains a byte value corresponding to the port name in the received LISM frame and a byte value corresponding to its own port name. Compare algebraically. In this case, since the loop to be configured this time is the same as the loop configured last time, if the sequence is normal, devices other than the device corresponding to the master port have the byte value corresponding to the received port name as Since it is smaller than the byte value corresponding to its own port name, the received LISM frame is returned to the FC-AL switch 201 instead of its own LISM frame. On the other hand, the master port returns its own LISM frame to the FC-AL switch 201.

  Thereby, when the same frame as the LISM frame of the transmitted master port is returned from each port (each device A101 to D104) (step St7: YES), the FC-AL switch 201 normally selects the master port. Recognize that After that, the loop configuration storage unit 301 stores information about loop configuration history a1 indicating which device is connected to which port in the currently configured loop, and master port a2 of the currently configured loop, that is, the master port The port name (8 bytes) of the selected device is stored (step St8). The process in step St8 is similarly performed after the above-described normal initialization sequence (step St3) is executed.

  On the other hand, when a different LISM frame is returned from each port (each device A101 to D104) (step St7: NO), the FC-AL switch 201 performs loop initialization from the beginning as an abnormal sequence. The information of the loop configuration history a1 and the master port a2 is deleted (step St9). After that, the FC-AL switch 201 transmits LIP to each of the devices A101 to D104 (step St10), returns to step St1, and performs loop reinitialization (normal sequence).

  Thereafter, the process proceeds to an address determination sequence, and addresses of the devices A101 to D104 are determined (step St11). The address determination sequence after determining the master port is not described in the present invention, and is a well-known technique, and is therefore omitted here.

  Therefore, according to the present embodiment, when loop initialization occurs, the FC-AL switch 201 is connected to the loop based on the loop configuration history a1 and master port a2 information in the loop configuration storage unit 301. If there is no change, the master port can be determined without performing the normal initialization sequence by notifying the devices A101 to D104 of the master port. That is, when loop initialization occurs, even when the device connected to the loop is not changed, it is possible to avoid a situation in which a predetermined initialization sequence is executed each time, and thereby the master port selection time can be greatly shortened.

  Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment as a representative example, and those skilled in the art will understand the contents of the claims. Based on the above, various modifications and changes can be made without departing from the scope of the present invention. These modified examples and modified examples also belong to the scope of the right of the present invention.

  For example, when at least a part of the functions of each part of the wireless FC-AL switch constituting the FC-AL system according to the above-described embodiment is realized using a program code, the program code and a recording medium for recording the program code Are included in the scope of the present invention. The program code in this case includes those program codes when the above functions are realized in cooperation with an operating system or other application software. As the recording medium, in addition to the hard disk and ROM described above, flexible disk, optical disk, magneto-optical disk, CD-ROM, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, magnetic tape, non-volatile A memory card or the like can be used.

  The present invention can be applied to FC-AL switches and uses of FC-AL systems using the same.

It is the schematic which shows the whole structure of the FC-AL system which concerns on embodiment of this invention. It is a figure which shows the data structure of the loop structure memory | storage part shown in FIG. It is a flowchart explaining operation | movement of the FC-AL switch shown in FIG. It is the schematic which shows the whole structure of the FC-AL system of a prior art example. It is a figure which shows the format of the LISM frame used with the FC-AL system of a prior art example.

Explanation of symbols

101-104 devices A-D
201 FC-AL switch 301 Loop configuration storage unit 302 Control unit 401 to 701 Reception line 402 to 702 Transmission line

Claims (16)

In an FC-AL switch that connects a plurality of devices as a plurality of ports constituting an FC-AL loop,
A loop configuration history showing a history of which port of the loop is connected to which device, and a port of a device selected as a master port for determining an address of each device connected to the loop among the plurality of devices Holding means for holding the name;
Master port selection means for selecting the master port of the loop configured last time as the master port of the loop that is configured this time based on the loop configuration history and the master port of the holding means at the time of initialization of the loop. FC-AL switch. The master port selection means includes
First determination means for determining whether or not the currently configured loop and its port connection state are the same as previously configured based on the loop configuration history of the holding means at the time of initialization of the loop;
When it is determined by the first determination means that the loop configured this time and the connection state of the port are the same as those configured last time, it is sent from the master port corresponding to the port name of the holding means. Notification means for notifying each device of an incoming LISM frame;
Second determination means for determining whether a LISM frame sent from each device in response to the notification means is the same as a LISM frame from the master port;
Master port recognition means for recognizing that the master port is normally selected when the second determination means determines that the LISM frame from each device is the same as the LISM frame from the master port. The FC-AL switch according to claim 1. The master port selection means includes
And further comprising means for storing a loop configuration history of the loop configured this time and a port name of the master port in the holding means after the master port recognizing means recognizes that the master port has been normally selected. The FC-AL switch according to claim 2. The master port selection means includes
When the second judging means judges that the LISM frame from each device is not the same as the LISM frame from the master port, the information held in the holding means is deleted, and the LIP is transmitted. 4. The FC-AL switch according to claim 2, further comprising means for performing a normal initialization sequence. The master port selection means includes
The first determination means further comprises means for performing a normal initialization sequence when it is determined that the loop configured this time and the connection state of its ports are not the same as those previously configured. The FC-AL switch according to any one of claims 2 to 4. The FC-AL switch according to any one of claims 1 to 5,
And a plurality of devices connected to the FC-AL switch. In a method for determining a master port of an FC-AL switch for connecting a plurality of devices as a plurality of ports constituting an FC-AL loop,
A loop configuration history showing a history of which port of the loop is connected to which device, and a port of a device selected as a master port for determining an address of each device connected to the loop among the plurality of devices Holding a name in the storage unit;
Selecting the master port of the previously configured loop as the master port of the loop that is configured this time, based on the loop configuration history and the master port held in the storage unit at the time of initialization of the loop. A method for determining a master port of an FC-AL switch. The step of selecting the master port includes
Determining whether or not the loop configured this time and the connection state of the port based on the loop configuration history of the storage unit at the time of initialization of the loop are the same as those previously configured;
If it is determined that the loop configured this time and the connection state of the port are the same as those configured last time, the LISM frame sent from the master port corresponding to the port name of the storage unit is Notifying the device;
In response to determining whether the LISM frame sent from each device is the same as the LISM frame from the master port;
8. The method according to claim 7, further comprising the step of recognizing that the master port is normally selected when it is determined that the LISM frame from each device is the same as the LISM frame from the master port. FC-AL switch master port determination method. The step of selecting the master port includes
9. The method according to claim 8, further comprising a step of storing a loop configuration history of the currently configured loop and a port name of the master port in the storage unit after the master port is recognized as being normally selected. FC-AL switch master port determination method. The step of selecting the master port includes
When it is determined that the LISM frame from each device is not the same as the LISM frame from the master port, the information stored in the storage unit is deleted, and the LIP is transmitted to perform a normal initialization sequence. The method for determining a master port of an FC-AL switch according to claim 8 or 9, further comprising a step. The step of selecting the master port includes
11. The method according to claim 8, further comprising a step of performing a normal initialization sequence when it is determined that the connection state of the loop configured this time and the port thereof is not the same as that previously configured. The master port determination method of the FC-AL switch of any one of Claims 1. In an FC-AL switch master port determination program for connecting a plurality of devices as a plurality of ports constituting an FC-AL loop,
On the computer,
A loop configuration history showing a history of which port of the loop is connected to which device, and a port of a device selected as a master port for determining an address of each device connected to the loop among the plurality of devices Holding a name in the storage unit;
Selecting the master port of the previously configured loop as the master port of the loop that is currently configured based on the loop configuration history and the master port stored in the storage unit when the loop is initialized. A master port determination program for an FC-AL switch characterized by The step of selecting the master port includes
Determining whether or not the loop configured this time and the connection state of the port based on the loop configuration history of the storage unit at the time of initialization of the loop are the same as those previously configured;
If it is determined that the loop configured this time and the connection state of the port are the same as those configured last time, the LISM frame sent from the master port corresponding to the port name of the storage unit is Notifying the device;
In response to determining whether the LISM frame sent from each device is the same as the LISM frame from the master port;
The method of claim 12, further comprising the step of recognizing that the master port is normally selected when it is determined that the LISM frame from each device is the same as the LISM frame from the master port. FC-AL switch master port decision program. The step of selecting the master port includes
14. The method according to claim 13, further comprising the step of storing a loop configuration history of the currently configured loop and a port name of the master port in the storage unit after it is recognized that the master port has been selected normally. FC-AL switch master port decision program. The step of selecting the master port includes
When it is determined that the LISM frame from each device is not the same as the LISM frame from the master port, the information stored in the storage unit is deleted, and the LIP is transmitted to perform a normal initialization sequence. 15. The program for determining a master port of an FC-AL switch according to claim 13 or 14, further comprising a step. The step of selecting the master port includes
16. The method according to claim 13, further comprising a step of performing a normal initialization sequence when it is determined that the connection state of the loop configured this time and the port thereof is not the same as that previously configured. The master port determination program for the FC-AL switch according to any one of the preceding claims.

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