Patent Publication Number: US-2004043755-A1

Title: Communication quality setting apparatus

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates to an apparatus, a method and a program of guaranteeing communication quality in an information processing system. More particularly, the invention relates to technology of guaranteeing the communication quality in a storage network system.  
       [0002] In recent days, a storage network system is likely to reach a significant role. The storage network system is used for directly connecting a large-scaled storage device to a network. As its example, SAN (Storage Area Network) or NAS (Network Attached Storage) have been proposed.  
       [0003]FIG. 15 illustrates an exemplary system arrangement of a storage network system in which a computer  10  uses a storage area  32  in a storage device  30 . The storage device  30  includes a plurality of ports  31  served as interfaces through which they may be connected with the network, a plurality of storage areas  32 , and a storage control unit  33  for controlling location of data from the computer  10  to the storage area  32 .  
       [0004] On the other hand, conventionally, QoS (Quality of Service) guaranteeing technology has been proposed as the technology of guaranteeing quality of communication between the computers  10  on the network or communication between the computer  10  and the port  31 . This technology is served as satisfying a request by securing a communication resource such as a band width on the network or processing packets in advance of another communication with respect to an inter-application communication like an internet phone or motion picture streaming that requests constant quality of communication as to a delay time or data loss rate.  
       [0005] As a representative example of QoS guaranteeing technology, RSVP (Resource ReserVation Protocol) regulated in RFC2205 may be referred. This technology is served to guarantee the quality of communication by sending a packet of requesting the QoS guarantee before data is transferred between computers and pre-securing communication resources such as a band width that meet a request in each network relay device located on the communication path between the computers.  
       [0006] The foregoing conventional QoS guaranteeing technology is an implementation of guaranteeing communication quality on the network between the computers. It does not realize the guarantee of communication quality in data communication between the computer  10  and the storage area  32  shown in FIG. 15.  
       [0007] Hence, in order to guarantee the quality of data communication between the computer  10  and the storage area  32 , a communication administrator has been required to calculate such a performance value to be guaranteed as satisfying the communication quality to be guaranteed between the computer  10  whose communication quality is to be guaranteed and the storage area  32  by associating with the information about the QoS guaranteeing request, configuration of the storage device, and the performance of each component and then to set the storage control unit  33  so that the communication quality may be guaranteed according to a calculated performance value to be guaranteed.  
       [0008] In order to calculate the performance value to be guaranteed, the communication administrator has been requested to grasp information about the arrangement of connections between the computers  10  and the storage areas  32  in a multi-to-multi manner as well as information about the performance of each device including the storage device  30 . It means that it has been difficult to substantially guarantee the quality of communication from the computer to the storage device. In particular, information about the performance value of each device including the storage device  30  may be often changed every moment. Hence, it is more difficult to grasp the information about the performance value of each device including the storage device  30 . In actual, no substantial quality guarantee of the communication is allowed between the computers and the storage areas of the storage device.  
       SUMMARY OF THE INVENTION  
       [0009] It is an object of the present invention to guarantee the quality of communication between the computers and the storage areas of a storage device in consideration of the performance value of each component included in the storage device.  
       [0010] In carrying out the object, according to an aspect of the invention, an apparatus of setting the communication quality is arranged to guarantee the quality of communication of a storage network system including storage devices which contain storage areas allocated for storing data, interfaces through which data is transferred, and storage control units for controlling location of data between the storage areas and the interfaces, and computers for writing and reading data on and from the storage area. Herein, the apparatus of setting the communication quality includes a guaranteed performance generating unit for determining a performance value to be guaranteed in each of the storage areas based on request information on communication quality guarantee, a performance value each interface of a storage device has, and a performance value each storage area of the storage device has. Further, the apparatus of setting the communication quality includes a guaranteed performance setting unit for guaranteeing the quality of communication between each computer and each storage area of the storage device by instructing the storage control unit to control location of data between the storage area and the interface according to the performance to be guaranteed.  
       [0011] Moreover, in the foregoing apparatus of setting the communication quality, it is preferable that the guaranteed performance generating unit is served to determine a performance value to be guaranteed in each storage area when one or more performance values of the storage areas in the storage device or one or more performance values of the storage areas in the storage device is changed, and then the guaranteed performance setting unit is served to instruct the storage control unit to control location of data between the storage area and the interface according to the performance value to be guaranteed.  
       [0012] In the foregoing apparatus of setting the communication quality, it is preferable that the guaranteed performance setting unit is served to instruct the storage control unit to terminate the quality guarantee of the communication when a certain length of time is passed since the quality guarantee of the communication is started.  
       [0013] Further, in the foregoing apparatus of setting the communication quality, it is preferable that the guaranteed performance setting unit is served to instruct the storage control unit to terminate the quality guarantee of the communication if a time when no data is transferred on the communication path to be guaranteed exceeds a certain length of time.  
       [0014] Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0015]FIG. 1 is a system block diagram showing a storage network system according to the first embodiment of the invention;  
     [0016]FIG. 2 is a table showing data to be passed from a QoS reading unit  41  to a guaranteed performance value generating unit  43  in the first embodiment;  
     [0017]FIG. 3 is a table showing data to be passed from a storage control information reading unit  42  to the guaranteed performance generating unit  43  in the first embodiment;  
     [0018]FIG. 4 is a table showing data to be passed from the guaranteed performance generating unit  43  to a guaranteed performance setting unit  44  included in the first and the second embodiments;  
     [0019]FIG. 5 is a flowchart illustrating a flow of process of the guaranteed performance generating unit  43  included in the first embodiment;  
     [0020]FIG. 6 is a system block diagram showing a storage network system of the second embodiment corresponding to that of the first embodiment;  
     [0021]FIG. 7 is a table showing data to be passed from the QoS reading unit  41  to the guaranteed performance generating unit  43  included in the second embodiment;  
     [0022]FIG. 8 is a table showing data to be passed from the storage control information reading unit  42  to the guaranteed performance generating unit  43  included in the second embodiment;  
     [0023]FIG. 9 is a flowchart illustrating a flow of process of the guaranteed performance generating unit  43  included in the second embodiment;  
     [0024]FIG. 10 is a system block diagram showing a storage network system of the third embodiment corresponding to that of the first embodiment;  
     [0025]FIG. 11 is a block diagram showing a storage device  30  included in the third embodiment;  
     [0026]FIG. 12 is a table showing data to be passed from the QoS reading unit  41  to the guaranteed performance generating unit  43  included in the third embodiment;  
     [0027]FIG. 13 is a table showing data to be passed from the storage control information reading unit  42  to the guaranteed performance generating unit  43  included in the third embodiment;  
     [0028]FIG. 14 is a table showing data to be passed from the guaranteed performance generating unit  43  to the guaranteed performance setting unit  44  included in the third embodiment; and  
     [0029]FIG. 15 is a block diagram showing a storage system having a storage device being directly connected with a network. 
    
    
     DESCRIPTION OF THE EMBODIMENTS  
     [0030] (First Embodiment)  
     [0031]FIG. 1 is a block diagram showing a system arrangement of a storage network system according to the present embodiment of the invention.  
     [0032] The storage network system of the first embodiment includes a plurality of computers  10 , a relay device  20 , a storage device  30 , and a QoS setting device  40 . In this embodiment, the QoS setting device  40  is illustrated as an independent device. In actual, it may be provided inside the storage device  30 .  
     [0033] The relay device  20  includes a connection control unit of controlling a connecting relation between the computers  10  and a storage device  30 , and a QoS control unit  21  of realizing the quality guarantee of the communication between the computers  10  and the storage device  30 . The relay device  20  may be a router or a gateway, for example. In this embodiment, only one relay device  20  is located between the computers  10  and the storage device  30 . Two or more relay devices may be located therebetween.  
     [0034] The QoS setting device  40  includes a QoS reading unit  41  of recording a guarantee-requested performance value on each communication route to which the value is inputted through a network management terminal, a storage control information reading unit  42  of obtaining a performance value to be guaranteed in a port  31  inside the storage device  30  and a performance value to be guaranteed in a storage area  32  inside the storage device  30 , a guaranteed performance generating unit  43  of determining a performance to be guaranteed on the basis of the guarantee-requested performance value, the performance value to be guaranteed in the port  31  inside the storage device  30 , and the performance value to be guaranteed in the storage area  32  inside the storage device  30 , and a guaranteed performance setting unit  44  of instructing the storage control unit  33  to control location of data between the port inside the storage device and the storage area so as to guarantee the performance value to be guaranteed.  
     [0035] In this and the other embodiments, a program functioned as the QoS reading unit  41 , the storage control information reading unit  42 , the guaranteed performance generating unit  43  or the guaranteed performance setting unit  44  is stored on a recording medium such as a CD-ROM and then saved on a magnetic disk or the like. Next, the program is loaded onto the memory of the QoS setting device  40  and then is executed. The medium on which the program is to be stored may be another storage medium other than the CD-ROM. Further, the program may be installed from the storage medium to the memory of the QoS setting device  40  or be used by accessing the storage medium through the network.  
     [0036] Herein, description will be oriented to the flow of process of the storage control information reading unit  42  included in the QoS setting device  40 .  
     [0037] The storage control information reading unit  42  instructs the device information obtaining unit  37  to measure the maximum performance value to be guaranteed by each of the ports  31  and the storage areas  32  inside the storage device  30 . In addition, if a value is pre-indicated as a performance value of the port  31  or the storage area  31 , the storage control information reading unit  42  may use the value as a performance value of the port  31  or the storage area  32  as the maximum performance value to be guaranteed.  
     [0038] The storage control information reading unit  42  is served to receive a maximum performance value to be guaranteed in each port  31  and each storage area  32  from the device information obtaining unit  37 , recording on a port performance table  110  the maximum performance value 112 to be guaranteed in the port  31  to be identified by each port ID  111 , and then record on a stored area performance table  120  a maximum performance value 122 to be guaranteed in the storage area  32  to be identified by each storage area ID  121 .  
     [0039] Moreover, the storage control information reading unit  42  instructs the device information obtaining unit  37  to obtain failure information of a port sensed by a port monitoring unit  36 .  
     [0040] The storage control information reading unit  42  instructs the device information obtaining unit  37  to obtain failure information of the storage area sensed by the storage area monitoring unit  35 .  
     [0041] The storage control information reading unit  42  is served to record the maximum performance value 112 to be guaranteed in the port  31  whose failure is sensed as zero (0) in the port performance table  110 .  
     [0042] The storage control information reading unit  42  is served to record the maximum performance value 112 to be guaranteed in the storage area  32  whose failure is sensed as zero (0) in the storage area performance table  120 .  
     [0043] The storage device  30  includes the port  31  served as a communication interface with the relay device  20 , the storage area  32  of holding data, a storage control unit  33  of executing access control of location of the data between the port  31  and the storage area  32  according to the control information table  34  having a data location map of the port  31  and the storage area  31  recorded thereon, a storage area monitoring unit  35  of obtaining a performance value of each storage area  31  or sensing a failure, a port monitoring unit  36  of obtaining a performance value of each port  31  and sensing a failure thereof, and a device information obtaining unit  37  of obtaining arrangement information of the storage device  30 . The storage area  32  may record data on a data block unit or a file unit. Or, it may be treated as a physical storage area or a logical storage area. Further, the device information obtaining unit  37  may be realized on the port  31 . Moreover, the storage control unit  33 , the storage area monitoring unit  35  or the port monitoring unit  36  may be located outside of the storage device.  
     [0044] The QoS setting device  40  includes a QoS reading unit  41  of obtaining QoS guarantee request information on the communication quality on each communication route between the computer  10  and the storage device  30  from the QoS control unit  21 , the storage control information reading unit  42  of obtaining a maximum performance value 112 to be guaranteed in the port  31  of the storage device  30  and a maximum performance value 122 to be guaranteed in the storage area  31  from the device information obtaining unit  37  of the storage device  30 , the guaranteed performance generating unit  43  of calculating the performance values 133 and 143 to be guaranteed on each communication route between the computer  10  and the storage area  32  of the storage device  30 , and the guaranteed performance setting unit  44  of instructing the storage device  30  or the relay device to guarantee the computed performance values 133 and 143.  
     [0045] The QoS reading unit  41  obtains the guarantee request information on each communication route from the QoS control unit  21 .  
     [0046]FIG. 2 shows the content of the guarantee request table  100  according to this embodiment.  
     [0047] The guarantee request table  100  includes a computer ID  101 , a port ID  102  by which the port  31  of the storage device  30  is to be identified, a storage area ID  103 , a guarantee-requested performance value 104 on each communication route specified by the computer ID, the port ID  102  and the storage area ID  103 , and a priority  105  on each specified communication route.  
     [0048] The computer ID  101  is an ID of the computer  10 , which is represented by an IP (Internet Protocol) address, an MAC (Media Access Control) address, a WWN (World Wide Name), and so forth.  
     [0049] The port ID  102  is an ID by which the port  31  is uniquely identified inside the storage area  30 .  
     [0050] The storage area ID  103  is an ID by which the storage area  31  is uniquely identified inside the storage device  30 . Each device may specify the communication route through the use of the storage area ID  103 , the computer ID, the port ID  102 , and the storage area ID  103 .  
     [0051] The guarantee-requested performance value 104 is a performance value including a band width, a delay time or a data loss ratio being guaranteed between the computer  10  and the port  31  by the relay device  20 . The guarantee-requested performance value 104 is a performance value on each path (route) among the computer  10  represented by the computer ID  101 , the port  31  represented by the port ID  102  and the storage area  32  represented by the storage area ID  103 . In addition, the network administrator enables to set the QoS control unit  21  to set the guarantee-requested performance value 104 through the GUI of the relay device  20 .  
     [0052] The priority  105  represents the priority sequence of communication quality guarantee on each communication route. In addition, the network administrator enables to set the priority  105  to the QoS control unit  21  through GUI of the relay device  20 . Further, if no priority  105  is set to the QoS control unit  21 , any priority  105  may have the same value.  
     [0053] The storage control information reading unit  42  obtains the port performance table  110  and the storage area performance table  120  from the device information obtaining unit  37  and stores the tables in itself.  
     [0054]FIG. 3 shows the contents of the port performance table  110  and the storage area performance table  120  included in this embodiment.  
     [0055] The port performance table  110  records the port ID  111  and the guaranteed maximum performance value 112 of the communication to be executed through each port  31  for each port ID.  
     [0056] The storage area performance table  120  records each storage area ID  121  and the maximum performance value 122 to be guaranteed on the overall communication to each storage area  32  for each storage areas ID  121 .  
     [0057] The guaranteed performance generating unit  43  calculates the performance values 133 and 143 to be guaranteed on each communication route of the computer  10  to the storage area  32  of the storage device  30  on the basis of the guarantee request table  100 , the port performance table  110  and the storage area performance table  120 . The guaranteed performance setting unit  44  instructs the relay device  20  and the storage control device  30  so as to control access between the port  31  and the storage area  32  according to the port QoS table  130  or the storage area QoS table  140  created by the guaranteed performance generating unit  43 .  
     [0058]FIG. 4 shows the contents of the port QoS table  130  and the storage area QoS table  140  according to this embodiment.  
     [0059] The port QoS table  130  stores a computer ID  131 , a storage area ID  132 , and a performance value 133 to be guaranteed to the storage area  32  specified on the communication route between the computer  10  specified by the computer ID  131  and the storage area  32  specified by the storage area ID  132 .  
     [0060] The storage area QoS table  140  stores a computer ID  141 , a port ID  142  for identifying the port of the storage device  30 , and a performance value 143 to be guaranteed to the port  31  specified on the communication route between the computer  10  specified by the computer ID  131  and the port  31  specified by the port ID  142 .  
     [0061]FIG. 5 is a flowchart showing a flow of process of the guaranteed performance generating unit  43  according to this embodiment.  
     [0062] The guaranteed performance generating unit  43  obtains the guarantee request table  100  shown in FIG. 2 from the QoS reading unit  41  (S 101 ).  
     [0063] The guaranteed performance generating unit  43  obtains the port performance table  110  and the storage area performance table  120  from the storage control information reading unit  42  (S 102 ).  
     [0064] The guaranteed performance generating unit  43  initializes the content of the port QoS table  130  and the content of the storage area QoS table  140  (S 103 ).  
     [0065] The guaranteed performance generating unit  43  specifies the communication with the highest priority  105  by the combination of the computer ID  101 , the port ID  102  and the storage area ID  103 , based on the guarantee request table  100  (S 104 ).  
     [0066] The guaranteed performance generating unit  43  specifies the maximum performance value 112 to be guaranteed of the port  32  of the storage device identified by the port ID  102  of the communication route specified in the step S 104 , based on the port performance table  110  (S 105 ).  
     [0067] The guaranteed performance generating unit  43  specifies the maximum performance value 122 to be guaranteed of the storage area  32  identified by the storage area ID  103  of the communication route specified in the step S 104 , based on the storage area performance table  120  (S 106 ).  
     [0068] The guaranteed performance generating unit  43  specifies the guarantee-requested performance value 104 on the communication route specified in the step S 104  based on the guarantee request table  100  and derives a minimum value from three values of the guarantee-requested performance value 104, the maximum performance value 112 to be guaranteed in the port  31  specified in the step S 105 , and the maximum performance value 122 to be guaranteed by the storage area  32  specified in the step S 106 .  
     [0069] The guaranteed performance generating unit  43  records this minimum value as a performance value to be guaranteed for the communication route specified in the step S 104  in the port QoS table  130  and the storage area QoS table  140  (S 107 ). If the performance values 133 and 143 to be guaranteed do not reach the guarantee-requested performance value 104, it is recognized as an error and the quality guarantee of communication against the communication route may be stopped.  
     [0070] If the performance value 133 to be guaranteed for the port on the specified communication route is recorded in the step S 107 , the guaranteed performance generating unit  43  rewrites the port performance table  110  so that the value derived by subtracting the performance value 133 to be guaranteed from the maximum performance value 112 to be guaranteed for the port  31  of the port performance table  110  may be the maximum performance value 112 to be guaranteed.  
     [0071] Likewise, if the performance value 143 to be guaranteed to the storage area  32  on the specified communication route is recorded in the step S 107 , the guaranteed performance generating unit  43  rewrites the storage area performance table  120  so that the value derived by subtracting the performance value 143 to be guaranteed from the maximum performance value 122 to be guaranteed for the storage area  32  of the storage area performance table  120  may be the maximum performance value 122 to be guaranteed.  
     [0072] The guaranteed performance generating unit  43  deletes the data on the communication roue specified in the step S 104  from the guarantee request table  100  (S 108 ).  
     [0073] The guaranteed performance generating unit  43  specifies the communication route with the next highest priority and repeats the processes of the steps S 104  to S 108  until the data of the guarantee request table  100  is made empty (S 109 ).  
     [0074] The guaranteed performance generating unit  43  sends the port QoS table  130  and the storage area QoS table  140  to the guaranteed performance setting unit  44  (S 110 ).  
     [0075] Herein, description will be oriented to the flow of process of the QoS reading unit  41 .  
     [0076] The QoS reading unit  41  periodically obtains information on a request for the quality guarantee of communication between the computer  10  and the port  31  from the QoS control unit  21 . In a case that the arrangement of the storage control unit  33  or the storage areas  32  is changed in the storage device  30 , in a case that the performance values of the port  31  and the storage area  32  are changed in the storage device, in a case that a failure takes place in the port  31  or the storage area  32 , or in a case that the content of the guarantee request table  100  is changed, the QoS control unit  21  may notify the QoS reading unit  41  of the information on the request for the quality guarantee of the communication.  
     [0077] The QoS reading unit  41  records the guarantee-requested performance value 104 and the priority  105  of the communication quality requested for each communication route specified by the computer ID  101 , the port ID  102  of the storage device and the storage area ID  103  from the information on the request for the quality guarantee of the communication and then sends the guarantee-requested performance value 104 and the priority  105  to the guaranteed performance generating unit  43 .  
     [0078] The QoS setting device  40  may start the process of the guaranteed performance generating unit  43  shown in FIG. 5 on the periodic timing or on the timing when the information on the request for the quality guarantee of communication is received from the QoS control unit  21 .  
     [0079] The guaranteed performance setting unit  44  obtains the port QoS table  130  and the storage area QoS table  140  from the guaranteed performance generating unit  43 .  
     [0080] The guaranteed performance setting unit  44  creates a control information table  34  so as to execute access control between the port  31  and the storage area  32  according to the obtained port QoS table  130  and storage area QoS table  140  and then sends the control information table  34  to the relay device  20  and the storage control unit  33 . In addition, the destination to which the guaranteed performance setting unit  44  sends the control information table  34  may be either one of the relay device  20  and the storage control unit  33 .  
     [0081] The storage control unit  33  executes control of accessing data between the port  31  and the storage area  32  according to the control information table  34 .  
     [0082] Likewise, the relay device  20  executes control of accessing data between the relay device  20  and the port  31  of the storage device  30  according to the control information table  34 .  
     [0083] This makes it possible to secure the communication quality to be guaranteed for each communication route between the computer  10  and each storage area  32  of the storage device  30 .  
     [0084] Further, by obtaining the information on the port or the storage area where a failure takes place, the communication passing through the port where the failure takes place may avoid securing a communication resource of the normal storage area. Conversely, the communication passing through the storage area where the failure takes place may avoid securing a communication resource of a normal port.  
     [0085] [Second Embodiment] 
     [0086]FIG. 6 shows a system arrangement of a storage network system according to this embodiment.  
     [0087] The storage network of this embodiment includes a plurality of computers  10 , a network  22  having a relay device, a storage device  30 , and a QoS setting device  40 .  
     [0088] In the first embodiment, the relay device  20  holds the quality guarantee of the communication between the computer  10  and the port  31 . On the other hand, in the second embodiment, the computer  10  sends a communication quality guarantee packet like an RSVP when the communication is executed.  
     [0089] The arrangements of the storage device  30  and the QoS setting device  40  are analogous to those of the first embodiment. However, the different respect of this embodiment from the first embodiment is that the QoS reading unit  41  is provided with means of obtaining the guarantee request information between the computer  10  and the port  31 , which corresponds to one piece of device information, not from the QoS control unit  21  but from the device information obtaining unit  37 .  
     [0090]FIG. 7 shows the content of the guarantee request table  200  of this embodiment.  
     [0091] The computer  10  sends the content of the guarantee request table shown in FIG. 7 as the data of a communication quality guarantee packet to the QoS reading unit  41  of the QoS setting device  40  through a network  25 .  
     [0092] The QoS reading unit  41  receives the communication quality guarantee packet from the computer  10 .  
     [0093] The guarantee request table  200  includes a QoS ID  201 , a type  202 , a computer ID  203 , a port ID  204 , a storage area ID  205 , a guarantee-requested performance value 206, a guarantee period  20 , and a timeout  208  recorded therein.  
     [0094] The QoS ID  201  is an identifier for each communication route whose quality is guaranteed. For example, it is represented by a communication connection ID or a packet ID.  
     [0095] The type  202  is data of representing if the quality guarantee of the communication is started or terminated.  
     [0096] The communication route whose quality is to be guaranteed is specified by the computer ID  203 , the port ID  204  and the storage area  205 .  
     [0097] The guarantee-requested performance value 206 indicates a performance value the network administrator enters and requests to the relay device  20  between each computer  10  and each port  31  of the storage device  30 .  
     [0098] The guarantee period  207  represents the time when the guarantee is continued since the quality guarantee of the communication is started.  
     [0099] The timeout  208  means that the quality guarantee of the communication is terminated if no data transfer is executed on the communication route continuously specified during the time given by the timeout  208  itself.  
     [0100] The guarantee period  207  and the timeout  208  are required to prevent the continuous securement of the communication resources such as a band width though a communication quality guarantee packet indicating the end of the communication quality guarantee does not reach the port  31  by the failure of the application on the computer  10  and the network  25 . In this embodiment, however, the guarantee period  207  and the timeout  208  are not inevitably included in the guarantee request table  200 .  
     [0101]FIG. 8 shows the port QoS data  210 , the storage area QoS data  220  included in this embodiment.  
     [0102] The port QoS data  210  represents a QoS ID  212 , a computer ID  213 , a storage area ID  214 , a maximum performance value 211 to be guaranteed for each port  31 , and a performance value 215 to be guaranteed for each port of the storage device on the communication route specified by the QoS ID  212 .  
     [0103] The storage area QoS data  220  is composed of a maximum performance value 221 to be guaranteed for each storage area  32 , a QoS ID  222 , a computer ID  223 , a port ID  224 , and a performance value 225 to be guaranteed for each storage area  32  on the communication route specified by the QoS ID  212 .  
     [0104]FIG. 9 shows the flow of process of the guaranteed performance generating unit  43  according to this embodiment.  
     [0105] The guaranteed performance generating unit  43  obtains from the QoS reading unit  41  the content of the guarantee request table  200  shown in FIG. 7 as the data of a communication quality guarantee packet and then specify the target of QoS by the QoS ID  201  of the guarantee request table  200  (S 201 ). When the port  31  receives the data of the communication quality guarantee packet, the storage control unit  33  may send the content of the guarantee request table  200  as the data of the communication quality guarantee packet to the guaranteed performance generating unit  43  through the device information obtaining unit  37 .  
     [0106] The guaranteed performance generating unit  43  periodically obtains the port QoS data  210  and the storage area QoS data  220  shown in FIG. 8 from the storage control information reading unit  42  (S 202 ). The guaranteed performance generating unit  43  may be arranged to obtain the port QoS data  210  and the storage area QoS data  220  in the case of receiving the data of the communication quality guarantee packet.  
     [0107] The guaranteed performance generating unit  43  determines if the guarantee-requested performance value 206 of the QoS target specified if the type of the QoS target specified in the step S 201  is “Start” does not exceed the maximum performance value to be guaranteed for the port specified by the port ID  204  of the specified QoS target and if the guarantee-requested performance value 206 of the QoS target specified in the step S 201  does not exceed the maximum performance  15  value to be guaranteed for the storage area  32  specified by the storage area ID  205  of the specified QoS target (S 204 ).  
     [0108] If either one of them exceeds the value, the guaranteed performance generating unit  43  notifies the guaranteed performance setting unit  44  of it as an error (S 208 ).  
     [0109] If neither of them exceed the values, the guaranteed performance generating unit  43  records the guaranteed request performance value 206 as the performance values 215 and 225 to be guaranteed of the QoS target specified in the step S 201  in the port QoS data  210  and the storage area QoS data  220  (S 205 ).  
     [0110] Like the first embodiment, the guaranteed performance generating unit  43  also may record in the port QoS data  210  and the storage area QoS data  220  the minimum value of the guarantee-requested performance value 206 of the QoS target, the maximum performance value to be guaranteed of the port  31 , and the maximum performance value to be guaranteed of the storage area  32  as the performance value 215 to be guaranteed of the QoS target specified in the step S 201 .  
     [0111] On the other hand, if the type  202  of the QOS target specified in the step S 201  is “End”, the guaranteed performance generating unit  43  deletes the data  212  to  215  of the specified QoS target from the port QoS data  210  and the storage area QoS data  220  (S 205 ). If the type  202  is “End”, the guaranteed performance generating unit  43  may instruct the relay device and the storage control unit  33  included in the network  25  to terminate the QoS for the communication route specified by the QoS ID  201  through the guaranteed performance setting unit  44 .  
     [0112] Next, in a case that the type  202  of the QoS target specified in the step S 201  is “Start”, the guaranteed performance generating unit  43  rewrites the port QoS data  210  so that a value derived by subtracting the performance value 215 to be guaranteed from the maximum performance value 211 to be guaranteed of the port ID  204  of the QoS target specified in the step S 201  may be a maximum performance value 211 to be further guaranteed by the port  31  represented by the port ID  204 .  
     [0113] Likewise, in a case that the type  202  of the QoS target specified in the step S 201  is “Start”, the guaranteed performance generating unit  43  rewrites the storage area QoS data so that the value derived by subtracting the performance value 225 to be guaranteed from the maximum guaranteed performance value 221 of the storage area ID  205  of the QoS target specified in the step S 201  may be a maximum performance value 221 to be further guaranteed by the storage area  32  represented by the storage area IS  205 .  
     [0114] The guaranteed performance generating unit  43  sends the port QoS data  210  and the storage area QoS data  220  to the guaranteed performance setting unit  44  (S 206 ).  
     [0115] In addition, the guaranteed performance generating unit  43  may be arranged to send not all the port QoS data  210  and the storage area QoS data  220  but only a changed part of the data as compared with the previously sent content.  
     [0116] The guaranteed performance setting unit  44  obtains the port QoS data  210  and the storage area QoS data  220  from the guaranteed performance generating unit  43 .  
     [0117] The guaranteed performance setting unit  44  creates the content of the control information table so as to control the access between the port  31  and the storage area  32  according to the port QoS data  210  and the storage area data  220 , and then sends the created content to the relay device included in the network  25  and the storage control unit  33 . The guaranteed performance setting unit  44  may be arranged to send the content of the control information table  34  to either one of the relay device included in the network  25  and the storage control unit  33  as a destination.  
     [0118] The storage control unit  33  executes the control of accessing data between the port  31  and the storage area  32  according to the control information table  34 .  
     [0119] Likewise, the relay device included in the network  25  executes the control of accessing data between the relay device and the port  31  of the storage device  30  according to the control information table  34 . This makes it possible to secure the communication quality to be required for each communication route between the computer  10  and the storage area  32  of the storage device  30 .  
     [0120] Further, the guaranteed performance generating unit  43  sends the port QoS data  210  and the storage area QoS data  220  to the guaranteed performance setting unit  44  and then instructs the relay device included in the network  25  or the storage control unit  33  to terminate the quality guarantee of the communication after the guarantee period  207  is passed.  
     [0121] In response to this instruction, the relay device included in the network  25  and the storage control unit  33  terminates the quality guarantee of the communication of the QoS target specified by the QoS ID  212 .  
     [0122] Further, the guaranteed performance generating unit  43  records as a QoS start time the time when the port QoS data  210  and the storage area QoS data  220  are sent to the guaranteed performance setting unit  44 .  
     [0123] The guaranteed performance generating unit  43  instructs the storage control information reading unit to obtain the time the final data transfer takes place on each communication after the timeout  208  is passed since the QoS start time.  
     [0124] If the time when the final data transfer takes place is later than the QoS start time, the guaranteed performance generating unit  43  resets the final time to the QoS start time. If earlier, the unit  43  instructs the storage control device  33  to terminate the quality guarantee of this communication.  
     [0125] In response to this indication, the relay device included in the network  25  and the storage control unit  33  terminates the quality guarantee of the communication of the QoS target specified by the QoS ID  212 . This allows the guaranteed performance generating unit  43  to store the data like the guarantee period  207  and the timeout  208 . Hence, if a communication quality guarantee termination packet does not reach the port  31 , the continuous use of the communication resources of the port  31  or the storage area  32  may be prevented.  
     [0126] In the foregoing description, when the computer  10  executes the communication, a communication quality guarantee packet is sent to the port  31 . Hence, the QoS setting device  40  is provided to guarantee the quality of the communication between the port  31  and the storage area  32  according to the communication quality guarantee packet.  
     [0127] [Third Embodiment] 
     [0128]FIG. 10 shows a system arrangement of a storage network system according to this embodiment.  
     [0129] In this embodiment, like the first embodiment, a QoS setting device is provided in the system having a plurality of computers  10 , a relay device  20  and a storage device  30 .  
     [0130]FIG. 11 shows an arrangement of the storage device  30  according to this embodiment.  
     [0131] The arrangement of the storage device  30  includes an FC relay unit  38  having a zoning table  39  that is requisite information to setting the zoning in addition to the arrangement of the first embodiment. In this embodiment, the storage device control unit  33  and the FC relay unit  39  are located inside the storage device  30 . In actual, they may be located outside of the storage device  30 .  
     [0132] A fibre channel is connected between the storage control unit  33  and the FC relay unit  38  or between the FC relay unit  38  and the storage area  32 . The storage control unit  33  and the FC relay unit provides FC ports  31   a  to  31   c  served as interfaces to the fibre channel.  
     [0133] Each of the FC ports  31   a  to  31   c  and the storage area  31  include WWNs allocated as identifiers thereto.  
     [0134] The zoning table  39  stores information about the zoning held by the FC relay unit  38 .  
     [0135] Herein, the zoning is a function of executing communication only between the specific instruments in the FC relay unit. For example, if WWNa, b, c is set to the specific zone, the FC relay unit is served to control so that the instrument with WWNa may be communicated with the instrument with WWNb,c but may not be communicated with the instrument with WWNd.  
     [0136]FIG. 13 shows a port performance table  300  of the storage control unit, a port performance table  310  of the FC relay unit, and a WWN table  320  of the storage area.  
     [0137] The port performance table  300  of the storage control unit represents the WWN  301  of the FC port  31   a  in the storage control unit  33  and the maximum performance value 302 to be guaranteed for each FC port  31   a . In actual, the WWN is represented by a 8-byte digit. In the illustration, it is simplified.  
     [0138] The port performance table  310  of the FC relay unit represents the WWN  311  of the FC ports  31   b  and  31   c  inside the FC relay unit and the maximum performance value 312 to be guaranteed for each FC port  31   b  or  31   c.    
     [0139] The WWN table  320  of the storage area represents the storage area ID  321  and the WWN  322  of each storage area  32 .  
     [0140] Herein, description will be oriented to the flow of process of the guaranteed performance generating unit according to this embodiment.  
     [0141] The guaranteed performance generating unit  43  obtains the guarantee request table  100  shown in FIG. 12 from the QoS reading device.  
     [0142] The guaranteed performance generating unit  43  obtains the port performance table  300  of the storage control unit, the port performance table  310  of the FC relay device, and the WWN table  320  of the storage area, all of which are shown in FIG. 13, from the storage control information reading unit  42 .  
     [0143] The guaranteed performance generating unit  43  specifies the communication route with the highest priority  105  on the basis of the guarantee request table  100 .  
     [0144] The guaranteed performance generating unit  43  specifies one set of WWNs  301  of the FC port that meets the guarantee-requested performance value 104, based on the guarantee-requested performance value 104 and the port performance table  300  of the storage control unit for the specified communication route.  
     [0145] The guaranteed performance generating unit  43  specifies two sets of WWNs  311  of the FC port that meets the guarantee-requested performance value 104, based on the guarantee-requested performance value 104 and the port performance table  310  of the FC relay unit for the specified communication route.  
     [0146] Further, the guaranteed performance generating unit  43  specifies the WWN  322  having the storage area ID  321  equal to the storage area ID  103  of the communication route specified by the WWN table  320  of the storage area, based on the WWN table  320  of the storage area.  
     [0147] The guaranteed performance generating unit  43  combines as one zone the WWN  332  of the storage area for the specified communication route, the WWN  301  of the FC port that meets the specified guarantee-requested performance value 104, and the WWN  31  of the FC port that meets the guarantee-requested performance value 104 and records it in a zone QoS table  340 .  
     [0148] Further, the guaranteed performance generating unit  43  specifies WWN  301  of a storage control unit port having a guaranteed performance value 302 satisfying the guarantee-requested performance value 104 with respect to a specified route, based on the guarantee request table  100  and a storage control unit port performance table  300 . The unit  43  then records, as WWN  334 , WWN  301  of the storage control unit port specified for each of the communication routes specified by the computer ID  331 , the port ID  332  and the storage area ID in the FC port QoS table  330 .  
     [0149] The guaranteed performance generating unit  43  deletes the WWN recorded on the FC port QoS table  330  from the port performance table  300  of the storage control unit and the port performance table  310  of the FC relay unit. Likewise, the guaranteed performance generating unit  43  deletes the communication route recorded on the FC port QoS table  330  from the guarantee request table  100 .  
     [0150] The guaranteed performance generating unit  43  specifies the communication route with the next highest priority based on the guarantee request table  100 . Then, the foregoing operation is repeated until the guarantee request table is made empty.  
     [0151]FIG. 14 is a view showing the FC port QoS table  330  and the zone QoS table  340  of this embodiment.  
     [0152] The guaranteed performance generating unit  43  sends the FC port QoS table  330  and the zone QoS table  340  shown in FIG. 14 to the guaranteed performance setting unit  44 .  
     [0153] The guaranteed performance setting unit  44  obtains the FC port QoS table  330  and the zone QoS table  340  from the guaranteed performance generating unit  43 .  
     [0154] The guaranteed performance setting unit  44  creates the control information table  34  according to the FC port QoS table  330  and sends the table  34  to the storage control unit  33 .  
     [0155] The storage control unit  33  controls the location of data between the port  31  and the storage area  32  according to the received control information table  34 .  
     [0156] This operation allows the communication route from the computer  10  represented by the computer ID  331  to the storage area  32  represented by the storage area ID  333  to be set to pass through the FC port  31   a  having the WWN  334  selected to meet the performance value to be guaranteed.  
     [0157] The guaranteed performance setting unit  44  creates the zoning table  39  according to the zone QoS table  340  and then sends the table  39  to the FC relay unit  39 .  
     [0158] The FC relay unit  39  sets the zoning according to the received zoning table  39 . This makes it possible to set the zone so as to meet the performance value to be guaranteed for each communication route.  
     [0159] The flow of process of the QoS reading unit  41  is analogous to that of the first embodiment. The description on the third embodiment has concerned with the arrangement that the relay device  20  holds the guarantee request table  100  like the first embodiment. In actual, however, like the second embodiment, the third may be applied to the case that the communication quality guarantee packet is sent to the port  31  when the computer  10  executes the communication.  
     [0160] In the foregoing description, if the storage device  30  further provides the FC relay unit  38 , the provision of the QoS setting device  40  realizes the quality guarantee of the communication between the computer  10  and the storage area  32 .  
     [0161] The present invention makes it possible to guarantee the communication quality between the computer and the storage area of the storage device in consideration of the components of the storage device and the performance values thereof.  
     [0162] It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.