JP2003316715A - Method for controlling computer having a plurality of ports, computer having the plurality of ports and method for controlling computer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively distribute the load of each port. <P>SOLUTION: In this method, a computer has a plurality of data I/O ports connected to an external device and a plurality of processors playing a role of the data I/O processing of the each port. The computer stores correspondence X between the port and a plurality of external ID given to the port so that the external device specifies the port. The computer changes the correspondence X according to the processing load of the processor. Other processors differing from the processor play a role of the processing of the port that the processor plays a role. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer having a plurality of ports.

[0002]

2. Description of the Related Art With the recent development of the IT industry, the demand for large-capacity storage such as disk array devices has increased. A general disk array device includes a considerable number of hard disk units and has a plurality of data input / output ports in order to efficiently connect to an external device that uses the hard disk units. Further, in such a disk array device, each port is provided with a port address for an external device that accesses the disk array device to specify the port. This address is, for example, SAN (St
orage area network) environment, it is a port address in fiber channel.

In recent years, a so-called I which connects a disk array device to the Internet using iSCSI or the like has been recently used.
Although the P storage is drawing attention, in the disk array device operated in such a form, the address is the IP address in the TCP / IP network. Since the disk array device can be directly IP-connected in this way, data can be directly delivered from the disk array device without intervening another system, and remote data backup can be performed in a seamless environment. The effect of is obtained.

[0004]

By the way, in a computer having a plurality of ports such as the above-mentioned disk array device, the processing load of each port does not always occur evenly for each port at each instant. For example, a situation may occur in which data input / output is concentrated only on a specific port, but data is hardly input / output on other ports. That is, although the resources are held sufficiently, the resources are not effectively used. Further, such concentration of data input / output to a specific port causes problems such as a decrease in communication speed and a decrease in throughput.

Here, as a mechanism for load distribution in a computer having a plurality of physical interfaces, for example, Japanese Patent Laid-Open No. 2001-16704 has a plurality of host interfaces and a plurality of control processors, and a control processor. Discloses a mechanism for distributing the load among the control processors by changing the logical device in charge of input / output processing according to the number of processings of itself. Since the technique disclosed in this publication does not perform load distribution among host interfaces, there is no change in the physical throughput of the host interface.

[0006] Japanese Unexamined Patent Publication No. 2000-332776 has a plurality of physical interfaces, and the destinations of IP packets transmitted and received according to the load status of each interface, the status of the network, the operating status of the partner interface, etc. And the source IP address is converted based on the determined rule, and the logical IP specified by the application
There is disclosed a mechanism for load balancing by using an address that is completely different from the address.

However, in the technique disclosed in this publication, when associating a physical address assigned to each interface with one logical IP address, the association is determined according to the load of each interface. This is for load balancing, and does not relate to a computer to which an address is assigned for each port by an external device to identify the port, unlike the disk array device. In addition, in a computer such as a disk array device that is assigned an address for each port, when realizing load distribution between ports, it is necessary to minimize the influence on the external device due to the realization of load distribution. You are also required to do so.

The present invention is intended to solve such a problem, and an object thereof is to provide a computer having a plurality of ports, a method of controlling a computer having a plurality of ports for effectively distributing the load of each port, and a plurality of methods. To provide a computer having a port.

[0009]

To achieve this object, the main invention of the present invention is to provide a plurality of data input / output ports connected to an external device and a plurality of data input / output processing units for the respective ports. And a processor for storing the association X between the port and a plurality of external IDs assigned to the port for the external device to identify the port.
A computer having a step of changing the association X according to a processing load of the processor, and causing another processor different from the processor to handle the processing of the port handled by the processor. It is characterized in that it has a plurality of ports for

Other features of the present invention will be apparent from the accompanying drawings and the description of this specification.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

=== Summary of Disclosure === At least the following will be made clear by the following disclosure. Multiple data input / output ports for connecting to external devices,
A method of controlling a computer having a plurality of processors in charge of data input / output processing of each port,
The computer and a plurality of external IDs given to the port by the external device to identify the port.
Stores the association X with the computer, the computer changes the association X according to the processing load of the processor, and the processing of the port in charge of the processor is performed by another processor different from the processor. A method of controlling a computer having a plurality of ports, characterized in that it has a step of being in charge.

Here, the above-mentioned association X is correspondence information between a port in a port management information table 9 described later and a plurality of IP addresses assigned to each port.

The external ID is an IP address,
The port may be specified by a MAC address.

The control method of the computer may include a step of changing the association X when the computer detects a failure of the processor.

In the method of controlling a computer having a plurality of ports, specifically, the processor monitors the processing load of the port it is in charge of, and the processing itself is performed according to the processing load. Sending a proxy request message to the other processor in charge of processing the other port, and whether the other processor accepts the proxy request message when receiving the proxy request message. And a step of transmitting a consent message stating that fact to the processor that has transmitted the proxy request message, and the processor or another processor has received the consent message. In this case, the plurality of external IDs associated with the port in charge of itself
And changing the association X so as to associate it with the port in charge of the processor that has transmitted the acceptance message.

Here, the processing load may be, for example, the number of instruction processes of the processor per unit time for each port for input / output processing of data input / output to / from the port. The proxy request message is a signal for setting a processing request flag in the port management information table 9 described later.

The method for controlling a computer having a plurality of ports may include a step of activating the step of changing the association X at a set time. The set time is, for example, the start time of nighttime batch processing in the banking system.

Also, in the method of controlling a computer having a plurality of ports, the computer associates information necessary for encrypted communication with the external device with the external ID and stores it as an association Y. The computer may include a step of changing the association X so that the state of the association Y is maintained as it is.

Here, the information required for the encrypted communication is, for example, SA information such as an encryption or decryption key required when constructing a VPN by IPsec described later, and the association Y is In the port management information table 9 which will be described later, it is the correspondence information between a plurality of IP addresses assigned to each port and SA information used on the communication path between each port and an external device under the VPN environment. is there.

A method of controlling a computer having a plurality of ports, wherein the computer inputs data to the storage volume according to one or a plurality of storage volumes and a data input / output request received through the port. Means for performing output processing, means for storing the ID of the external device that uses the storage volume and the ID of the storage volume that can be used by each of the external devices as an association Z, the external ID and the external device And a means for storing the ID of the device as the association P, the computer changing the association X so as to maintain the states of the association Z and the association P as they are. Good.

Here, the correspondence Z is an IP address assigned to each port in a port management information table 9 described later and a logical unit which is set to be accessible by an external device to which the port is connected. This is information corresponding to the number.

The correspondence P is a plurality of I's assigned to each port in the port management information table 9 described later.
It is correspondence information between the P address and the IP address of an external device such as a host to which each port is connected.

A route control device such as a router and a plurality of data input / output ports connected to the route control device,
A method for controlling a computer system including a computer having a plurality of processors in charge of data input / output processing of each port, wherein a path control device provides an external ID assigned to the port to identify the port. The association P between the port and the port is stored, and the route control device
Transmitting the data packet input externally to the port specified by the external ID described as the destination in the data packet, and causing the computer to specify the port and the external device specify the port. Storing a correspondence X with a plurality of external IDs assigned to the port, the computer changing the correspondence X according to the processing load of the processor, and the port of the port in charge of the processor. A step of assigning a process to another processor different from the processor; a step of causing a computer to transmit the change content to the route control device; and a route control device receiving the change content and performing the association P And a step of changing.

=== Embodiment === <System Configuration> FIG. 1 is a schematic configuration diagram of a storage system including a disk array device 13 as an embodiment of the present invention. In the figure, the disk array device 13 is connected to the Internet 10 via a router 14e, and communicates with a host 11 or a remote host 12 such as a general-purpose computer or a PC which is also connected to the Internet. The remote host 12 is installed at a location remote from the host 11.

The disk array device 13 has a plurality of ports 1. The disk array device 13 is a logical unit LU (Logi
calUnit) 8, a disk controller 7 that controls the input / output of data to / from a logical unit, data transferred between a plurality of ports 1 and the disk controller 7, and data read from the logical unit 8. It has a cache memory 6 for temporary storage and a shared memory 5 accessed from a plurality of ports 1.

Data input / output to / from each port 1 is performed by an interface unit 2 provided for each port 1 for transmitting / receiving communication data to / from a host 11 or a remote host 12, and data input / output processing at port 1. And other ports 1
A processor (3) in charge of communication with the computer, and a DMA (Di) that controls data transfer between the port 1 and the cache memory 6.
rect Memory Access) Control unit 4. In addition,
In addition to the configuration in which the processor 3 is assigned to each port 1 as shown in the figure, one processor 3 may perform input / output processing of a plurality of ports 1.

<Assignment of IP Address to Port> FIG. 2 is a diagram showing an IP address assigned to each device and each port 1 in the storage system of the present invention. A MAC address, which is a unique physical address given to each port, is given to each port 1. Further, each port 1 is assigned one or more IP addresses for the host 11 and the remote host 12 to identify the port 1. In the figure, since multiple IP addresses are assigned to each port 1, the same port 1
The processor 3 in charge of the input / output processing can perform the processing requested by the host 11 or the remote host 12 for each IP address of the port 1 in parallel.

As shown in FIG. 2, each port 1 of the disk array device 13 is an Ethernet (registered trademark) 1
5 to the router 14e. Router 14e
It is configured to include a port connected to the Internet 10, a port connected to the Ethernet 15, a routing table, and an ARP (Address Resolution Protocol) cache 16. ARP cache 16
Stores a correspondence table of MAC addresses and IP addresses of each port 1 connected to the Ethernet 15 generated by ARP.

Host 11 or remote host 12
Are divided into groups such as companies. The host 11a belongs to the same host group as the host 11b and the remote host 12a. Also, the host 11a
Is connected to the Internet 10 via a router by constructing a LAN with the host 11b. The host 11
Alternatively, although one IP address is assigned to the remote host 12, a plurality of IP addresses may be assigned.

In the above configuration, transmission of communication data such as an IP packet addressed to the IP address x1 of the port 1a from the host 11a is performed as follows, for example. First, the host 11a confirms the MAC address of the router 14a by ARP. Next, the host 11a uses the MAC address of the router 14a as the destination MAC.
Address and IP address x1 of port 1a as destination I
The IP packet described as the P address is used by the router 14a.
Send to. The router 14a transmits the IP packet received from the host 11a to the router 14e via the Internet 10. Also, the router 14e uses ARP
When the cache 16 is searched and the IP address x1 described in the transmitted IP packet is registered in the ARP cache 16, the destination MAC address of the IP packet is described as the MAC address of the port 1a. Change and send to port 1a. In this way, the communication data for the IP address x1 of the port 1a is transmitted from the host 11a.

<Port Management Information Table> The IP address and the like assigned to each port 1 are stored in the port management information table 9 stored in the shared memory 5 of the disk array device 13. FIG. 3 is a diagram for explaining an example thereof.

The port management information table 9 includes port numbers, own IP addresses assigned to the respective ports, IP addresses of the host 11 or remote host 12 to which the port 1 is connected, and the port 1 as described later. V
SA (Security Association) information used when PN (Virtual Private Network) is built, and port 1
Host 11 or remote host 12 to connect to
Number (Logical Unit Number) of the logical unit 8 that is set to be accessible to the
In the process of load balancing between them, the processor 3 in charge of the processing of the port 1 is configured with a processing request flag which is set when requesting the substitution of its own processing.

The SA information, which will be described in detail later, is I
Psec (Security Architecture for the Internet Proto
col) refers to information such as an encryption key, a decryption key, an authentication algorithm, and an encryption algorithm that are shared by devices that communicate with each other when establishing a logical connection. Further, the correspondence between the host 11 or the remote host 12 and the LUN accessible by them is, for example, the host 1
1 and the remote host 12, the management terminal of the disk array device, etc., and is set by the user or operator.

The configuration information other than the SA information in the port management information table 9 is determined when the disk array device 13 is configured or expanded, but the IP addresses of the host 11 and remote host 12 change dynamically. In some cases, RADIUS (Remote Authentication Dial
The disk array device 13 may detect the IP address of the host 11 or the remote host 12 and update the port management information table 9 by an authentication server using the In User Service (RFC2138) protocol.

Regarding SA information, IKE (Internet Key Exchang) which is a protocol for exchanging SA information is used.
e) In the process of protocol processing, the corresponding SA information in the port management information table 9 may be registered.

<Processing Procedure for Load Distribution Between Ports> Next, the process of load distribution between ports 1 by the disk array device 13 according to the present invention will be described with reference to the flowchart of FIG. In the following, from the state corresponding to # 2 in FIG. 3, the I of port 1a in which an increase in load is detected is detected.
The process is described until the P address is changed so as to be assigned to the port 1b, and the process in charge of the port 1a is in charge of the port 1b.

First, the IP of the port 1a from the host 11a
When a heavy load processing request such as a remote copy process (remote data backup) is addressed to the address y1 (S400), the processor 3a in charge of the process of the port 1a processes the port 1a in charge of itself. It is determined whether load balancing is necessary according to the load (S4
01). Note that the processing load is, for example, the number of instruction processes of the processor 3 per unit time required for input / output processing of data input / output to / from the port 1.

When it is determined that the load distribution is necessary, the processor 3a has a process that can be requested to another port 1 among the IP addresses (x1, y1, z1) given to the port 1a from the host 11a. Determine if This determination is performed based on, for example, a criterion such as whether or not a session addressed to the IP address is ongoing (S402). In the following description, it is assumed that, as a result of the determination, the processing requested with the IP address (x1, z1) as a destination can be requested to another port.

Next, the processor 3a uses the shared memory 5
Is accessed and the processing request flag for the IP address (x1, z1) in the port management information table 9 is set (S403). FIG. 5 shows the port management information table 9 in this state. Each processor 3a, 3b, 3c in charge of processing of each port sequentially accesses the shared memory 5 by the polling method and monitors in real time whether the processing request flag is set in the port management information table 9. is doing.

Processor 3 in charge of processing port 1b
b is the IP address (x
If the processing request flag for (1, z1) is set (S404), the IP address (x1,
IP address (a1, a2) of the host corresponding to z1)
Determines whether to check the connection with the port 1b with the IP address of the host belonging to the permitted host group (S4).
05), depending on the processing load of the port 1b which it is in charge of, determines whether to accept the request for the processing requested to the IP address (x1, z1) (S40).
6). Here, in the case where the processor 3b approves the substitute processing from the processor 3a, the processor 3b transmits an approval message to the processor 1a via the shared memory 5 (S407).

Upon receiving the acceptance message from the processor 3b, the processor 3a receives the IP address (x1, z
1) is released (S408), the release is notified to the processor 3b, and the content of the port management information table 9 in the shared memory 5 is changed so that the IP address (x1, z1) is assigned to the processor 3b ( In S409, the data related to the requested processing is transmitted to the processor 3b with the IP address (x1, z1) as the destination. In addition,
The change of the port management information table 9 may be performed by the processor 3a that has requested the proxy processing as described above, or may be performed by the processor 3b that has transmitted the request acceptance message.

As described above, port 1a and port 1
Load distribution with b is performed. By applying such a load balancing process, the disk array device can perform load balancing according to the processing load of the processor 3 in charge of the processing of the port 1, and effectively utilize the resources of the processor 3. be able to. FIG. 6 shows the state of the port management information table 9 at this point.

In the above description, whether or not load balancing is necessary is determined only when a processing request with a large load is received (S400). However, the present invention is not limited to this, and whether load balancing is required in real time is performed. You may decide whether it is.

On the other hand, in the above processing, the processor 3c in charge of the processing of the port 1c also monitors in real time whether the processing request flag is set, like the processor 3b, and the processing request flag is on. In this case, it determines whether the IP address (x1, z1) belongs to its own group. In the figure, the processor 3c has an IP address (x1, z1).
However, since it does not correspond to the IP address of the host group B permitted to connect to the port 1c which is in charge of processing by itself, the processing request from the processor 3a is not accepted. As a result, exclusive control for access from different host groups is performed.

By the way, in the above processing, the IP address allocation is changed according to the processing load of the processor 3 in charge of the processing of the port 1.
The IP address allocation may be changed when a failure of the port 1 is detected or when the disk array device 13 is maintained or inspected.

Further, a scheduler for determining the timing of changing the IP address allocation is run on the disk array device 13, and triggered by the start of heavy load processing such as nighttime batch processing in the banking system, for example. The IP address allocation to each port may be changed.

=== Notification to Router === By the way, when the above-mentioned IP address assignment is changed, the router 14e is notified of the relationship between the updated port and IP address, and the router 14e is notified. The table in the ARP cache 16 stored by itself is updated based on the above. In other words, the notification of the router 14e changes the data flow and realizes load distribution.

When the ARP cache 16 automatically deletes an unused IP address for a certain period of time and a new association between the port 1 and the IP address which is not maintained in the cache occurs. Then, the information in the cache is updated.

Further, in the present embodiment, when it is desired to reflect the contents of the update of the IP address in the disk array device 13 in the ARP cache 16, a method of shortening the time until the deletion or the “Host Requirements Co.
mmunication (RFC1122) ”, a method of notifying that there is a problem from the Internet layer to the link layer and deleting the corresponding information in the ARP cache 16,
Method of using UNARP (RFC1868), so that the port 1 that receives the above-mentioned acceptance message deletes the correspondence information of the released IP address with respect to the port 1 to the router 14e when releasing the IP address. A method of requesting it is possible.

=== Encrypted Communication === By the way, as one of the methods for ensuring the communication security on the Internet, by encrypting the data flowing through the communication path and constructing a virtual private network on the Internet. A technique for enabling secure communication is known.

IPsec (RFC1825-1829) uses this VPN
Is a protocol for building. In IPsec, communication devices share information such as an authentication algorithm, an encryption algorithm, and an encryption key, and the data flowing through the communication path is encrypted or decrypted based on the information. This shared relationship is the above-mentioned SA (security association). In IPsec, information exchange for establishing this SA is performed prior to communication, and the protocol therefor is, for example, IKE (Internet Key Exchang).
e). Japanese Patent Laid-Open No. 2000-224219 discloses that
The disk array device 13 communicates with the external device by IP
NAT (Network
A technique for implementing both Address Translation) and VPN in parallel is disclosed. In addition, Japanese Patent Laid-Open No. 2001-3313
Japanese Unexamined Patent Publication No. 80 discloses a technique relating to a computer system and an encryption / decryption method for realizing security and improving throughput in a remote system.

According to the present invention, the construction of a VPN based on IPsec and the load distribution can be simultaneously realized on a computer. Further, it is possible to guarantee load distribution and QoS (Quality of Service) on the computer.

Further, when changing the allocation of the IP address to the port 1, the disk array device 13 also maintains the association of the SA information corresponding to the IP address of the port 1 with the port management information table 9 The port 1 to which the IP address is assigned by updating
VP that has already been constructed even when the
It is possible to prevent the N logical connections from being interrupted.

=== Session Maintenance and Load Balancing === As a technique related to the IP storage connected to the Internet, there is a technique for connecting a plurality of storages under the control of a load balancing device to balance the load. Many load balancing apparatuses use the NAT function as a load balancing mechanism to associate one IP address with a plurality of IP addresses assigned to individual storages for load balancing. In this method, since the IP address is converted in association with the IP address, the security function of IPsec described above does not work. Therefore, for example, in the above-mentioned Japanese Patent Application Laid-Open No. 2000-224219, the NAT function is expanded to achieve compatibility between VPN and NAT.

There is also a load balancer that does not use NAT, and in this case, each IP storage as a load balancer is identified by a MAC address.
However, even in this case, the IP data itself is encrypted, and in a session (for example, online shopping using a Web page, it is necessary to proceed with processing with the same server during the provision of a series of services. If it is necessary to maintain a series of processes as a session), the load cannot be effectively distributed.

In the present invention, for an IP address for which a session is continuing, the association between the IP address and port 1 is not changed. Therefore, it is possible to effectively balance the load while maintaining the session.

=== Movement of accessible LU information ==
= When the IP address allocation to port 1 is changed, the host 11 that is the connection destination of port 1 and is associated with the IP address in the port management information table 9
Alternatively, the number LUN of the above-mentioned logical unit 8 which is set to be accessible to the remote host 12 maintains the correspondence with the IP address as it is.

As a result, the access restriction to the logical unit set in association with the IP address is maintained as it is even after the allocation of the IP address to the port is changed. Further, in the above-mentioned VPN environment, exclusion of data stored on the computer can be realized for each constructed VPN.

[0059]

According to the method of controlling a computer having a plurality of ports of the present invention, it is possible to provide a method of controlling a computer having a plurality of ports and a computer having a plurality of ports for effectively distributing the load of each port. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a storage system including a disk array device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an IP address assigned to each device and each port according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of a port management information table according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a process of load distribution between ports according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a process of load distribution between ports according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a process of load distribution between ports according to an embodiment of the present invention.

[Explanation of symbols]

1a, 1b, 1c, 1n ports 2a, 2b, 2c, 2n interface section 3a, 3b, 3c, 3n CPU 4a, 4b, 4c, 4n DMA controller 5 shared memory 6 cache memory 7 Storage controller 8a, 8b, 8c, 8d Logical unit 9 Port management information table 10 Internet 11a, 11b, 11c host 12a, 12b Remote host 13 Disk array device 14a, 14b, 14c, 14d, 14e routers

Claims (11)

[Claims] 1. A method of controlling a computer, comprising: a plurality of data input / output ports connected to an external device; and a plurality of processors in charge of data input / output processing of the respective ports, the computer comprising: The external device stores the association X with one or more external IDs assigned to the port to identify the port, and the computer changes the association X according to the processing load of the processor, A method of controlling a computer having a plurality of ports, comprising the step of causing another processor different from the processor to handle the processing of the port handled by the processor. 2. The method of controlling a computer having a plurality of ports according to claim 1, further comprising the step of changing the association X when the computer detects a failure of the processor. 3. The processor monitors the processing load of the port that it is in charge of, and sends a proxy request message for requesting the proxy of the process performed by itself to the process of another port according to the processing load. The step of transmitting to the other processor in charge, and the other processor, when receiving the proxy request message, decides whether to accept the proxy, and if so, describes that fact. A step of transmitting a consent message to the processor which has transmitted the proxy request message, and the processor or another processor, when the acceptance message is received, a plurality of ports associated with the port to which the processor is in charge The external ID is associated with the port in charge of the processor that has transmitted the acceptance message. Control method for a computer having a plurality of ports according to claim 1, characterized in that it comprises a step of changing the urchin the association X, a. 4. The step of changing the association X according to the processing load of the processor includes the instruction processing of the processor per unit time for the input / output processing of the data input / output to / from the port. 2. The method of controlling a computer having a plurality of ports according to claim 1, wherein the step of changing the association according to the number of computers. 5. The method of controlling a computer having a plurality of ports according to claim 1, wherein the computer has a step of activating a step of changing the association X at a set time. 6. The computer stores information necessary for encrypted communication with the external device in association with the external ID as association Y, and the computer keeps the state of association Y as it is. 2. The method of controlling a computer having multiple ports according to claim 1, further comprising the step of changing the association X so as to maintain it. 7. The method of controlling a computer having a plurality of ports according to claim 6, wherein the information required for the encrypted communication is an encryption or decryption key assigned to each of the external IDs. . 8. The computer utilizes one or more storage volumes, means for performing data input / output processing for the storage volume in response to a data input / output request received through the port, and the storage volume. I of the external device
D, means for storing the ID of the storage volume that can be used by each of the external devices as an association Z, and means for storing the external ID and the ID of the external device as an association P. , The computer associates the association Z with the association P
The method of controlling a computer having a plurality of ports according to claim 1, further comprising the step of changing the association X so that the state of 1 is maintained as it is. 9. The method of controlling a computer having a plurality of ports according to claim 1, wherein the external ID is an IP address and the port is specified by a MAC address. 10. A computer having a plurality of data input / output ports connected to an external device, and a plurality of processors in charge of data input / output processing of each port, wherein the computer has the port and the external device. The association X with one or more external IDs assigned to the port to identify the port is stored, the computer changes the association X according to the processing load of the processor, and the processor A computer having a plurality of ports, comprising means for causing another processor different from the processor to handle the processing of the port in charge. 11. A control of a computer system including a route control device, a plurality of data input / output ports connected to the route control device, and a computer having a plurality of processors in charge of data input / output processing of each port. A routing control device stores an association P of an external ID assigned to the port to identify the port and the port, and the routing control device stores the externally input data packet Transmitting the data packet to the port specified by the external ID described as the destination in the data packet, and the computer assigns the port and the external device to the port to identify the port 1 or Storing a correspondence X with a plurality of external IDs; A step of changing the association X and causing a processor other than the processor to take charge of processing of the port that the processor is in charge of; and a step of causing the computer to send the change content to the route control device. And a step of causing the path control device to receive the change content and change the association P, the control method of the computer system.