Abstract:
A computer system including a copy source volume and a copy target volume which may be selectably PAIRED or SPLIT. User management information stores: an entry indicating that a first user is permitted to effect a PAIR operation and a PATH operation; and, an entry indicating that a second user is permitted to effect a PATH operation. Operation management information indicates permitted PATH and PAIR operations in relation to each user and a volume&#39;s PAIR or SPLIT status, and stores: an entry indicating that the first user is permitted to effect the PAIR operation in which the PAIR status is PAIR, or is SPLIT WITH BACKUP DISABLED; and, an entry indicating that the second user is permitted to effect the PATH operations in which the PAIR status is SPLIT WITH BACKUP ENABLED. PAIR management information stores the PAIR status and the BACKUP ENABLED or DISABLED status.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This is a continuation of U.S. application Ser. No. 11/121,142, filed May 4, 2005. This application relates to and claims priority from Japanese Patent Application No. 2005-049371, filed on Feb. 24, 2005. The entirety of the contents and subject matter of all of the above is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The invention relates to a volume management method for managing volumes in which the authority for operating an identical volume in a storage is regulated to avoid misoperations by users and to allow normal operation of the volume when a plurality of users manage the identical volume depending on the task of the users employing the volumes. 
         [0003]    With an increasing amount of storage data, computer systems under corporate or other operation management include an increasing number of computer systems using high-capacity storage, and computer systems using a plurality of storages interconnected by SAN (Storage Area Network) which is a storage-dedicated network (primarily Fibre Channel) or IP (Internet Protocol) in which computers share a high capacity of data distributed among a plurality of storages. Moreover, for improved storage availability and other purposes, many storages have been provided with an increased number of, and enhanced capabilities. In the computer systems as described above, the increased amount of data to be managed complicates the operation management of storage, and also increases its cost. For this reason, a technique has been proposed for dividing a management range to divide users managing a plurality of storages in a storage network and high-capacity storages (e.g., Japanese Laid-Open Patent Application 2003-330622, hereinafter referred to as Patent Document 1). 
         [0004]    In the technique disclosed in Patent Document 1, accessible volumes are assigned to users or hosts and their management authorities can be set up. According to Patent Document 1, the management range of the users can be clarified for each volume. 
         [0005]    In another technique for enhanced capabilities of storage, in order to avoid the lowering of performance of an on-line process during a backup process, volumes in a storage are duplexed to replicate data for the on-line process. A server performing the backup process (backup server) treats the data of the replicated volume as a replication source to transfer the data to a backup destination (e.g., Japanese Laid-Open Patent Application 2002-41345, hereinafter referred to as Patent Document 2). This technique enables fast backup without burdening the on-line process. 
         [0006]    These conventional methods have the following problems. 
         [0007]    In a conventional technique as disclosed in Patent Document 2, in light of the volume replication technique for storage, the process of the backup server is triggered by the termination of replication. Thus a functionally different process is triggered by the change of status of the volume. However, continuous execution of these processes is assumed. No reference is made to any influence on replicated volumes that might be operated by another manager having a task other than backup, that is, to the manager&#39;s operation authority over the volumes. In a series of backup processes as disclosed in Patent Document 2, if another manager deleted any path connected with a backup server during the process of obtaining replicated volume data in a storage, the backup processes could not terminate successfully. In other words, without permission of the manager performing backup, the configuration of the volume may be arbitrarily changed by another manager. For this reason, a mechanism is required for managing authorities over volumes. 
         [0008]    The conventional technique as disclosed in Patent Document 1 may sometimes address the above problems. However, division of the management range is a resource of the storage system including volumes. Operating a storage system involves various operations on the same volume. Such operations include, for example, setting of a path that defines a route for accessing data from a host, replication between volumes for data backup, and write protection on the volume for volume data protection. Since these operations are functionally different from the viewpoint of tasks, even a single volume may be managed by different managers for respective tasks. In this case, according to Patent Document 1, the same volume may be assigned to different managers. Therefore the same volume can be managed for each task by a different manager. 
         [0009]    However, as disclosed in Patent Document 2, storage operations may change the status of volumes. In addition, some functions include storage operations assuming a plurality of settings for the storage operations. Such functions include, for example, replication between volumes described above. In this function, data written on a volume from a host is directly replicated to another volume within the storage, or on another storage, without the intervention of the host. However, the manager operating the replication between the volumes is only responsible for controlling the replication between the volumes and monitoring the status of volume replication on the assumption that the path has been set up. The path may be set up by another manager. This situation involves a plurality of instances of management in the same volume where, according to Patent Document 1, a management authority over paths is granted to a manager of path setup. 
         [0010]    However, in the case of Patent Document 1, for example, even when a manager of volume replication manages the setting of replication, an authority for deleting paths of volumes is still granted to a manager of path setup. If the manager of path setup erroneously deletes a path, or creates a path to another host, then the setting of replication by the manager of volume replication becomes inoperative. More specifically, the change of path setup forces the manager of volume replication to manage volume replication under the condition that no data I/O is issued from the host, contrary to the assumption of the manager. Therefore the assumption of the manager of volume replication is violated. 
       SUMMARY 
       [0011]    It is an object of the invention to provide a computer system, a managing computer, a host computer, and a volume management method being capable of regulating authorities of users and avoiding misoperations. 
         [0012]    In order to solve the above problems, according to the invention, users, such as host managers, capable of operating volumes are regulated depending on the status (hereinafter also referred to as “attributes”) of the volumes. More specifically, the operation authorities of host managers of a storage system are grasped on the basis of the status of the volumes to restrict or change the operation authorities of the different host managers over the same volume. For example, when a volume is being replicated, the status of the volume being replicated is managed. Thus, when the volume is being replicated, there is a host manager of volume replication, and other host managers, such as path setup managers, are restricted so that they do not execute path operations on the volume managed by the host manager of volume replication. In this way, path setup managers are prevented from erroneously deleting paths or creating irrelevant paths. Thus the storage system can be consistently operated and managed without corrupting the operating environment of the host manager of volume replication. That is, the operation authorities of host managers are changed depending on the status of volumes to regulate the authorities of the users and avoid misoperations. In other words, the setup authorities of the users are changed upon change of attribute of the volume, so that the settings of a storage by coexisting host managers can be made consistent without corrupting the storage operating environment. 
         [0013]    More specifically, the invention is directed to a computer system comprising at least one storage having one or more volumes served as a storage region; a managing computer for managing the storage; and a plurality of host computers, each host computer being used by a user capable of obtaining an operation authority over the volume in the storage, where the storage, the managing computer, and the host computers being interconnected via a network, and two or more host managers being capable of using an identical volume, wherein upon obtaining an operation content of one user for at least one of the volumes over which two or more users have the operation authority, the managing computer determines from an attribute of the volume and the operation authority of the two or more users over the volume whether the operation content is executable, and when the operation content is not executable, the operation content is restrained. 
         [0014]    According to the invention, the setup authorities of the users are changed upon change of attribute of the volume. As a result, the settings of a storage system by coexisting users can be made consistent, any misoperations by the users can be avoided, and corruption of the storage operating environment can be avoided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  shows the configuration of a storage system for managing volumes in a first embodiment. 
           [0016]      FIG. 2  shows a first example of tables used in the storage system for managing volumes in the first embodiment. 
           [0017]      FIG. 3  shows a second example of tables used in the storage system for managing volumes in the first embodiment. 
           [0018]      FIG. 4  shows a third example of tables used in the storage system for managing volumes in the first embodiment. 
           [0019]      FIG. 5  shows a fourth example of tables used in the storage system for managing volumes in the first embodiment. 
           [0020]      FIG. 6  shows a fifth example of tables used in the storage system for managing volumes in the first embodiment. 
           [0021]      FIG. 7  shows a sixth example of tables used in the storage system for managing volumes in the first embodiment. 
           [0022]      FIG. 8  shows a seventh example of tables used in the storage system for managing volumes in the first embodiment. 
           [0023]      FIG. 9  shows an example flow chart illustrating a procedure of changing volume operation authorities in the first embodiment. 
           [0024]      FIG. 10  shows an example of displaying volume operation authorities in the first embodiment. 
           [0025]      FIG. 11  shows the configuration of a storage system for managing volumes in a second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    Preferred embodiments for carrying out the invention will now be described. 
         [0027]    In the following, embodiments of a computer system, a managing computer, a host computer, and a volume management method according to the invention are described in detail with reference to the drawings. 
       First Embodiment 
       [0028]    The first embodiment will now be described.  FIG. 1  shows the configuration of a storage system for managing volumes, which is the first embodiment of a computer system of the invention. Storage  120  comprises at least one volume  125  that is a managed area for storing data actually operated by a computer (e.g., host  110 ), an interface (I/F)  122  for transmitting and receiving data I/O related to reading/writing the volume  125  and for communicating with a managing computer  100  and the like, a CPU  121  for actually controlling the storage, and a memory  123 . The interface  122  may include separate communication devices for different forms of communication (e.g., IP (Internet Protocol) for communication with the managing computer  100  and FC (Fibre Channel) for data I/O with the host  110 ). The memory  123  contains a storage configuration program  124 , which is embodied by being executed by the CPU  121 . The storage configuration program  124  is a program for managing the configuration of the storage  120 , and has storage functions including a function of using the volumes  125  to create a plurality of replicated volumes for a particular volume, a function of allowing the host  110  to recognize the volume  125  via the interface  122  (hereinafter also referred to as “path setup function”), a function of restricting hosts allowed for recognition after the path setup function is used, and a function of protecting the volume  125  from data write. The volume  125  may be a hard disk, or a logical volume of hard disks in a RAID configuration. In a backup system, the volume  125  may be a removable medium such as a tape or DVD for taking backup of data. In these cases, the storage  120  may be a medium implemented by a hard disk, a device having a plurality of hard disks to implement a volume in RAID configuration, a tape library that is a device for automatically exchanging tapes served as removable media, or a DVD library for automatically exchanging DVDs. Note that a “path” used herein refers to a path in a storage and a path between the host and the storage. 
         [0029]    The managing computer  100  comprises a CPU  101 , memory  103 , and an interface  102  for communicating with the storage  120  and the host  110 . Storage coordination program  104 , volume authority management program  105 , and host coordination program  106  for the managing computer are intended for implementing the processing of the embodiment of the invention. The storage coordination program  104 , volume authority management program  105 , and host coordination program  106  are stored in the memory  103  of the managing computer  100  and embodied by being executed by the CPU  101 . Storage management information  107  and task management information  108  are information used in the storage coordination program  104 , volume authority management program  105 , and host coordination program  106 . 
         [0030]    The host  110  is a computer that transmits and receives data I/O via an interface  112  to/from the volume  125  of the storage  120 , and stores and/or edits host data in the volume  125 . The host  110  comprises the interface  112  described above, a CPU  111 , and a memory  113 . When the host  110  is managed by the managing computer  100 , managing computer coordination program  116  on the memory  113  of the host  110  is used to transmit and receive information to/from the managing computer  100  via the interface  112 . Task program  114  of the host  110  is a program for executing tasks operated on the host  110 . These tasks (applications) include data management for updating and/or creating data on the volume  125 , and backup management for replicating data. Storage coordination program  115  for the host is a program for obtaining the information and directing the settings of the storage configuration in coordination with the storage configuration program  124  of the storage  120 . The task program  114 , storage coordination program  115 , and managing computer coordination program  116  stored in the memory  113  are embodied by being executed by the CPU  111 . The interface  112 , which is connected with the managing computer  100  and the storage  120 , may include separate interfaces when a protocol such as TCP/IP is used for transmitting and receiving information to/from the managing computer  100  and another protocol such as Fibre Channel is used for the storage  120 , that is, when they are connected using different protocols. In other words, the interface  112  may be composed of a single interface device when, for example, the same protocol is used for the managing computer  100  and the storage  120  for transmitting and receiving data of the host  110 . 
         [0031]      FIG. 2  illustrates an example set of tables in the storage management information  107  used in each program executed on the managing computer  100  in the first embodiment. The storage management information  107  includes a volume management table  200 , port management table  210 , and pair management table  220 . 
         [0032]    The volume management table  200  stores volume ID  201  identifying a volume, storage ID  202  identifying a storage, storage volume ID  203  identifying a volume in each storage, port ID  204  identifying a port when a path is set up, host ID  205  identifying security information used for restricting access from particular hosts when a path is set up, guard  206  storing information on whether any guard such as write protection is applied to the volume, and backup permission  207  storing information on whether the volume is intended for backup when a backup task is present. This table  200  is used for identifying volumes in a plurality of storages when the managing computer  100  manages the plurality of storages. 
         [0033]    For example, the volume having a volume ID  201  of “VOL1” is illustrated as having a path set up at a port with a port ID  204  of “PORT-A”, having a security setup so that only the host with a host ID  205  of “HOST-A” can make a reference, and being subjected to the guard described above. The volumes having no information (blank) in the port ID  204  and host ID  205  indicate that they have no path setup and security setup, respectively. For each volume, “NOT GUARDED” is stored when the above-described guard is not set up, and “GUARDED” is stored when the guard is set up. In addition, for each volume, “NOT PERMITTED” is stored when the above-described backup permission is absent, and “PERMITTED” is stored when the backup permission is present. 
         [0034]    The host ID  205  is an identifier of a host that can be identified in a storage. Therefore, for example, if the interface  122  of the storage  120  is Fibre Channel, its World Wide Name can be used as an identifier. The information of the host ID  205  may be sent from the managing computer coordination program  116  of the host  110  to the host coordination program  106  of the managing computer  100  to determine the validity of the data of the host ID  205 . 
         [0035]    When a plurality of paths need to be set up for a single volume ID, that is, when a plurality of ports need to be registered, information having the same volume ID may be stored in a different rows in the volume management table  200 . In addition, when security is applied to a plurality of hosts for the same path, that is, for the same set of volume ID and port ID, a plurality of instances of this path with different host IDs may be stored in the volume management table  200 . 
         [0036]    There may be a plurality of types of guard  206  (e.g., write protect only, read/write protect, etc.). However, for simplicity, it is assumed herein that the guard is set up by a common manager, and the embodiment is described with reference to the identification of whether the guard is set up. 
         [0037]    The port management table  210  stores port ID  211  identifying a port, storage ID  212  identifying a storage, and storage port ID  213  identifying a port in each storage. This table is used for identifying ports in a plurality of storages when the managing computer  100  manages the plurality of storages. 
         [0038]    The pair management table  220  stores pair ID  221  identifying each pair relation, replication source  222  indicating the volume ID of a replication source, replication destination  223  indicating the volume ID of a replication destination, and status  224  indicating a pair status. The information of the replication source  222  and the replication destination  223 , which has the same value as the volume ID  201  in the volume management table  200 , stores the pair relation between the volumes. For example, the pair having pair ID “1” represents a pair relation from the volume “VOL1” of the replication source to the volume “VOL2” of the replication destination, and a pair status of pairing, that is, a status indicating that data is being copied from the replication source to the replication destination. 
         [0039]    It is assumed here that the status  224  in the pair management table  220  can have the following types of pair status. Status “PAIRING” indicates that, as described above, data in the volume of the replication source is being written to the replication destination volume for synchronization of data, or they are actually in synchronization. Status “PAIR SPLIT” indicates that data copy from the replication source volume to the replication destination volume is suspended in order to save data within a certain time period after the data is synchronized during pairing. The status thus indicates that the data in the replication source volume within a time period of pair split is also reflected in the replication destination volume. Status “NOT PAIRED” refers to the status of a volume that is not involved in pair definition. 
         [0040]      FIG. 3  illustrates an example set of tables in the task management information  108  used in each program executed on the managing computer  100  in the first embodiment of the invention. Task operation table  300  stores information including task  301  representing the name of a user task and operation  302  indicating the storage operation actually executed by the task  301 . The operation “PAIR” indicated here refers to an operation of replicating a volume, and the operation “PATH” refers to an operation of path setup. 
         [0041]    For example, the task “STORAGE” indicates that pair and path operations are executed in a storage setup that can be executed by the storage configuration program  124 . While the guard setup described below can also be executed by the storage configuration program  124 , the guard setup is excluded from this storage task because another host manager is assigned. 
         [0042]    The task “BACKUP” refers to a task on a backup server providing a host with a backup task to execute replication from the volume of replication source to the volume of replication destination. However, it indicates that the actual storage operation is executed as a path operation for the backup server and the volume. 
         [0043]    The task “GUARD SETUP” is a task of guard setup in coordination with the task program and the storage coordination program located in the host. It indicates that a guard setup operation is executed for the storage operation. 
         [0044]    User management table  310  stores user ID  311  identifying a user, task  312  indicating a task of the user, managed resource  313  that is a set of resources managed by the user in the task  312 , and password  314  of the user. 
         [0045]    The information stored in the managed resource  313  includes volumes and the like that are also indicated in the volume ID  201 , port ID  211 , and host ID  205 . 
         [0046]    For example, a user having a user ID  311  of “1” is illustrated as having a task of storage operation, and being able to manage resources including volumes “VOL1” and “VOL2”, ports “PORT-A” and “PORT-A1”, and hosts “HOST-A” and “HOST-B”. 
         [0047]    A user having a user ID  311  of “2” is illustrated as having a task of backup, and being able to manage resources including volumes “VOL2” and “VOL7”, ports “PORT-A1” and “PORT-C”, and host “HOST-B”. 
         [0048]    A user having a user ID  311  of “3” is illustrated as having a task of guard setup, and being able to manage resources including volume “VOL1” and host “HOST-A”. 
         [0049]      FIG. 4  illustrates another example set of tables in the task management information  108  used in each program executed on the managing computer  100  in the first embodiment. Task operation table  400  has the same form as the task operation table  300 , but indicates tasks in a different representation. The tasks in this representation can also be viewed as a form of tasks obtained by dividing the task “STORAGE” in the task operation table  300  into individual operations and managing each operation by a separately assigned host manager. 
         [0050]    The task operation table  400  stores information including task  401  representing the name of a user task and operation  402  indicating the storage operation actually executed by the task  401 . For example, the task “PATH” indicates that path operations are executed in a storage setup that can be executed by the storage configuration program  124 . The task “PAIR” indicates that pair operations are executed in a storage setup that can be executed by the storage configuration program  124 . 
         [0051]    User management table  410  has the same form as the user management table  310 , but represents an example of defining users in a different management system. 
         [0052]    The user management table  410  stores user ID  411  identifying a user, task  412  indicating a task of the user, managed resource  413  that is a set of resources managed by the user, and password  414  of the user. 
         [0053]    The information stored in the managed resource includes volumes and the like that are also indicated in the volume ID  201 , port ID  211 , and host ID  205 . 
         [0054]    For example, a user having a user ID  411  of “11” is illustrated as having a task of path operation, and being able to manage resources including volumes “VOL1”, “VOL2”, “VOL5”, and “VOL6”, ports “PORT-A” and “PORT-B”, and hosts “HOST-A” and “HOST-B”. It thus indicates that the user can set up a path with “VOL1” and “PORT-A”, and another path with “VOL5” and “PORT-B”. 
         [0055]    A user having a user ID  411  of “12” is illustrated as being able to set up a pair using volumes “VOL1” and “VOL5”, and another pair using “HOST-A” and “HOST-C” via the host  110 . Here, the pair setup via the host  110  requires that the user having a user ID  411  of “11” cause “HOST-A” to set up paths for “VOL1” and “VOL5”, respectively. 
         [0056]      FIG. 5  illustrates an example table in the task management information  108  used in each program executed on the managing computer  100  in the first embodiment. Shared volume operation management table  500  is a table for use with a volume shared by a plurality of users to associate the status of the volume with tasks that can use the volume. It is assumed that the tasks indicated here are those examples indicated in the task operation table  300  and the user management table  310  shown in  FIG. 3 . 
         [0057]    The shared volume operation management table  500  stores information including operation  501  representing an operation content for the volume shared by a plurality of users, volume status  502  defined as information for distinguishing volume operations, task  503  indicating the task of a user authorized for the operation of the shared volume, dynamic setup  504  indicating whether the operation  501  on the shared volume is set up on the occasion of change of status to the volume status  502 , and resource delegation  505  defined with respect to the delegation of the authority over the resource used in the operation on the shared volume. 
         [0058]    The volume status  502  indicates guard  206  and backup permission  207  in the volume management table  200  and status  224  in the pair management table  220  of the storage management information  107 . Absence of information stored in this volume status  502  indicates that the volume operation is allowed irrespective of the volume status. 
         [0059]    The task  503  is information on the task in the user management table  310  and the task operation table  300 . The example shown in  FIG. 5  includes an entry where no information is stored in the task  503 . This means that the operation authority is not granted to users of any task. 
         [0060]    The dynamic setup  504  may store a value (information) of “YES”. The value “YES” being stored indicates that, when the volume gets into the status indicated in the volume status  502 , the operation  501  to be executed in the task  503 , if it has not been set up yet, is automatically set up without the intervention of user operation. Absence of information stored in the dynamic setup  504  indicates that the above process of dynamic setup is not to be executed. 
         [0061]    The resource delegation  505  may store a value (information) of “YES”. The value “YES” being stored indicates that, when the volume gets into the status indicated in the volume status  502 , the managed resources associated with the shared volume of the user managing the resources before getting into the volume status  502  are delegated. 
         [0062]    For example, the operation “PATH” normally has a task  503  “STORAGE” or “BACKUP” in view of the example shown in  FIG. 3 . However, when the volume status  502  is “GUARDED”, that is, when the shared volume is subjected to guard setup, the user task capable of using the volume is changed to the task  503  “GUARD SETUP”. At this time, the resources associated with the shared volume used for a normally managed task and with the operation “PATH” for the shared volume are delegated to the task  503  “GUARD SETUP”. That is, a normally managed user task is assigned to “GUARD SETUP”. This defines a consistent execution of tasks by using the volume status to change the users of the task capable of storage operation, that is, to change the storage operation authority of the users. 
         [0063]    Users executing each task may have various levels. For example, some users may have a high level of operation authority in guard setup. Other users may have a low level of operation authority so that they can execute guard setup only on a certain occasion (e.g., they can execute guard setup only on pair split). In this case, a plurality of instances of the task specified in the task  503  are set up and ranked. For example, suppose that user A is responsible for the guard setup task, user B is responsible for the storage task, both users having a high level of operation authority, and user C is responsible for the guard setup task and has a low level of operation authority. In the pair operation with the status of “GUARDED”, users of the guard setup task have the authority. For the three users described above, users A, B, and C are registered on the task  503  so that the operation authority is granted to users A, B, and C in this order (priority). In this way, if there are no users at the level of user A and only the users at the level of users B and C are managing the shared volume, then the users at the level of users B, that is, the users of the storage task, will execute the pair operation even in the status of “GUARDED”. 
         [0064]    It may also occur that users at the same level execute the same task and manage the same volume. In this case, the user executing the task earlier is set to have the right to managed resources and finishes the operation of the task. For example, in the pair operation of setting up a pair by a user, the task  503  may be registered so that the user has the operation authority over the associated volumes and that the other users at the same level are excluded from the operation authority. Otherwise, without this limitation, any users at the same level may be treated as being capable of the operation. 
         [0065]      FIG. 6  illustrates an example table indicating which particular user can operate the volume shared by various users, where the particular user is determined from the volume status based on the information in the task operation table  300 , user management table  310 , and shared volume operation management table  500  in the first embodiment. 
         [0066]    Shared volume operation management correspondence table  600  indicates information including shared volume  601  indicating the volume ID of a volume shared by the users, operation  602  representing an operation content for the volume shared by a plurality of users, volume status  603  defined as information for distinguishing volume operations, allowed user  604  indicating a user that can execute the operation  602  on the shared volume  601  in the case of the volume status  603 , dynamic setup  605  indicating whether the operation  602  on the shared volume is set up on the occasion of change of status to the volume status  603 , and resource delegation  606  defined with respect to the delegation of the operation authority over the resource used in the operation on the shared volume. The dynamic setup  605  and resource delegation  606  have the same meaning as the dynamic setup  504  and resource delegation  505  in the shared volume operation management table  500  described above. 
         [0067]    Absence of a value (information) stored in the volume status  603  indicates that the volume operation is allowed irrespective of the volume status. For example, the guard setup for “VOL1” indicates that the guard operation can be executed by the user having user ID “3” irrespective of the status of the volume. 
         [0068]    Absence of a value stored in the allowed user  604  indicates that no user has the operation authority indicated in the operation  602 . For example, it can be seen in the volume “VOL2” that the allowed user  604  has no value in the case of “PAIR SPLIT, BACKUP PERMITTED”. In this case, no user has the authority over the operation indicated in the operation  602 , that is, pair operation. 
         [0069]    The shared volume operation management correspondence table  600  may have information automatically created from the shared volume operation management table  500 , user management table  310 , and task operation table  300 . Alternatively, the information may be registered as the task management information  108  of the managing computer prior to the storage operation. The shared volume operation management table  500  and the shared volume operation management correspondence table  600  may be prevented from coexisting. Alternatively, if they coexist, determination may be made as to which table is preferred. 
         [0070]    For example, the shared volumes are “VOL1” and “VOL2”. If the volume status of “VOL1” is “GUARDED”, then the user capable of using the shared volume in the path operation is found to be “3”, that is, a user of the guard setup task according to the user management table  310 . In addition, the resource delegation  606  indicates “YES”. Therefore, in this case, resources such as ports and hosts required for the path operation on “VOL1” are also delegated to the user having user ID “3” responsible for guard setup, who will execute the path operation on behalf of the user having user ID “1”. 
         [0071]    The volume status  603  in the shared volume operation management correspondence table  600  needs to store only the status for the operation by the sharing users. That is, “VOL1” is shared only by the user having user ID “1” and the user having user ID “3”, and does not depend on the pair status, so that it does not need to store information on the pair status. 
         [0072]      FIG. 7  illustrates an example table in the task management information  108  used in each program executed on the managing computer  100  in the first embodiment. Shared volume operation management table  700 , which has the same form as the shared volume operation management table  500 , is a table for use with a volume shared by a plurality of users to associate the status of the volume with tasks that can use the volume. It is assumed that the tasks are those examples indicated in the task operation table  400  and the user management table  410  shown in  FIG. 4 . 
         [0073]    The shared volume operation management table  700  stores information including operation  701  representing an operation on the volume shared by a plurality of users, volume status  702  defined as information for distinguishing volume operations, task  703  indicating the task of a user authorized for the operation of the shared volume, dynamic setup  704  indicating whether the operation  701  on the shared volume is set up on the occasion of change of status to the volume status  702 , and resource delegation  705  defined with respect to the delegation of the operation authority over the resource used in the operation on the shared volume. 
         [0074]    For example, in the operation “PATH”, the volume status  702  of “NOT PAIRED” indicates that the user of the task “PATH” executes the operation. If the volume status  702  is “PAIRED”, the user of the task “PAIR” executes the operation, and the resource delegation  705  is set to “YES”. 
         [0075]      FIG. 8  illustrates an example indicating which particular user can operate the volume shared by various users, where the particular user is determined from the volume status based on the information in the task operation table  400 , user management table  410 , and shared volume operation management table  700  in the first embodiment. 
         [0076]    Shared volume operation management correspondence table  800 , which has the same form as the shared volume operation management correspondence table  600 , indicates information including shared volume  801  indicating the volume ID of a volume shared by the users, operation  802  representing an operation content for the volume shared by a plurality of users, volume status  803  defined as information for distinguishing volume operations, allowed user  804  indicating a user that can execute the operation  802  on the shared volume  801  in the case of the volume status  803 , dynamic setup  805  indicating whether the operation  802  on the shared volume is set up on the occasion of change of status to the volume status  803 , and resource delegation  806  defined with respect to the delegation of the operation authority over the resource used in the operation on the shared volume. The dynamic setup  805  and resource delegation  806  have the same meaning as the dynamic setup  704  and resource delegation  705  in the shared volume operation management table  700  described above. 
         [0077]    In the same light as the shared volume operation management correspondence table  600 , the shared volume operation management correspondence table  800  may have information automatically created from the shared volume operation management table  700 , user management table  410 , and task operation table  400 . Alternatively, the information may be registered as the task management information  108  of the managing computer prior to the storage operation. The shared volume operation management table  700  and the shared volume operation management correspondence table  800  may be prevented from coexisting. Alternatively, if they coexist, determination may be made as to which table is preferred. 
         [0078]    For example, the shared resources (volumes)  801  are “VOL1” and “VOL5”. If the volume status of “VOL1” is “PAIRED”, then the user capable of using the shared volume in the path operation is found to be “12”, that is, a user of the pair task. In addition, the resource delegation  806  indicates “YES”. Therefore, in this case, resources such as ports and hosts required for the path operation on “VOL1” are also delegated to the user having user ID “12” responsible for the pair task, who will execute the path operation on behalf of the user having user ID “11”. 
         [0079]      FIG. 9  shows an example flow chart illustrating a procedure of changing volume operation authorities by a user of a volume on the managing computer in the first embodiment. In  FIG. 9 , steps  906  and  909  are executed by the storage coordination program  104 , and the other steps are executed by the volume authority management program  105 . In addition, at steps  906  and  909 , the storage setup may be executed via a host. In this case, it may be executed by also directing the host coordination program  106 . 
         [0080]    The managing computer  100  receives a storage setup request from a user (step  900 ). The received request includes a user ID, password, resource to be used, and requested operation. Here, if the requesting user or the password of the user is inconsistent with the information in the user management table, it is treated as an error and the process is terminated. At this time the cause of the error may be presented to the operator of the storage setup. 
         [0081]    Next, based on the request received at step  900 , it is determined whether the operation of the received storage setup request is within the user task (step  901 ). That is, referring to the table in  FIG. 3  by way of example, it is determined whether the user task in the user management table  310  corresponds to the operation specified in the task operation table  300 . If the operation is within the user task, the process continues to step  902 . Otherwise, the process continues to step  912 , where an error message indicating that the operation is out of the user task is communicated to the user and the process is terminated. 
         [0082]    For example, suppose a case where a user having a user ID  311  of “2” in the user management table  310  requests a pair operation. The task of the user having a user ID  311  of “2” in the user management table  310  is the backup task. According to the task operation table  310 , it can be seen that only the path operation is permitted as the backup task. Therefore, it is determined that execution of the pair operation by a user having user ID “2” is out of the user task. The process then continues to step  912 , where an error message indicating that the pair operation is out of the user task is communicated to the user and the process is terminated. In this case, if the requested operation for the user is a path operation, it is within the user task for a user having user ID “2”. Therefore the process continues to step  902 . 
         [0083]    At step  902 , based on the request received at step  900 , it is determined whether the received storage setup request is within the managed resource. If the request is within the managed resource, the process continues to step  903 . Otherwise, the process continues to step  912 , where an error message indicating that the request is out of the managed resource is communicated to the user and the process is terminated. 
         [0084]    For example, suppose a case where a user having a user ID  311  of “1” in the user management table  310  tries to set up a path using the port “PORT-A” and volume “VOL3”. “VOL3” is not registered at the managed resource  313  of the user having a user ID  311  of “1” in the user management table  310 . Therefore the process continues to step  912 , where an error message indicating that “VOL3” is out of the managed resource is communicated to the user and the process is terminated. In this case, if the volume “VOL2” rather than the volume “VOL3” is requested, it is within the managed resource for a user having user ID “1”. Therefore the process continues to step  903 . 
         [0085]    At step  903 , it is determined whether the volume requested at step  900  is shared with other users, that is, whether it is managed by other users with the same volume being served as the managed resource. If it is shared, the process continues to step  904 . Otherwise, the process continues to step  906 . 
         [0086]    For example, if a user having a user ID  311  of “1” in the user management table  310  requests at step  900  for a path operation on “VOL2”, it is found that the user having a user ID  311  of “2” also has “VOL2” as the managed resource. Therefore, in this case, the process continues to step  904 . 
         [0087]    At step  904 , the status of the volume requested at step  900  is obtained. 
         [0088]    For example, referring to the data of the volume management table  200  and pair management table  220  in  FIG. 2  by way of example, if the volume intended for setup is “VOL2”, the status of “VOL2” is determined to be “NOT GUARDED” from guard  206  in the volume management table  200  and “PAIRING” from status  224  in the pair management table  220 . The process then continues to step  905 . 
         [0089]    At step  905 , the possibility of operating the volume requested at step  900  depends on the volume status obtained at step  904 . The possibility of storage setup, which depends on the status of the volume, is determined by comparing the volume status and the volume operation authority in the shared volume operation management table and the tables in the storage configuration information  107 . If the storage setup is possible, the process continues to step  906 . Otherwise, the storage setup is not possible and the process continues to step  912 , where an error message thereof is presented to the storage setup requester and the process is terminated. 
         [0090]    For example, if the storage setup requester is the user having user ID “2” in the user management table  310 , the requested operation is the path operation, and the volume to be used is “VOL2”, then the status of “VOL2” is found to be “NOT GUARDED” and “PAIRING”. In addition, it is determined from the shared volume operation management table  500  that the volume is associated with a user of the storage task. The user having user ID “2” is a backup user, and thus has no authority for operation in this volume status. That is, the user having user ID “2” cannot execute path operations on “VOL2”. Therefore the process continues to step  912 , where an error message is presented indicating lack of authority for the requested operation in light of the volume status at the time of the request and the process is terminated. At this time, if the user has user ID “1” instead of “2”, the user has the operation authority, and the process will continue to step  906 , because the user having user ID “1” is responsible for the storage task according to the user management table  310 . 
         [0091]    In addition, for example, if the storage setup requester is the user having user ID “11” in the user management table  410 , the requested operation is the path operation, and the volume to be used is “VOL5”, then the status of “VOL5” is found to be “NOT GUARDED” and “PAIRING”. In addition, it is determined from the shared volume operation management table  700  that the volume is associated with a user of the path task, and thus the user has no authority for operation in this volume status. That is, the user having user ID “11” cannot execute path operations on “VOL5”. Therefore the process continues to step  912 , where an error message is presented indicating lack of authority for the requested operation in light of the volume status at the time of the request and the process is terminated. At this time, if the user has user ID “12”, the user has the operation authority, and the process will continue to step  906 , because the user having user ID “12” is responsible for the pair task according to the user management table  410 . 
         [0092]    At step  906 , the storage setup associated with the request received at step  900  is executed by directing the storage configuration program  124  of the storage  120  from the storage coordination program  104 . The process then continues to step  907 . 
         [0093]    According to the process so far, the volume operation authority can be consistently granted in response to the request of the user. Influence of the operation by other users can be excluded, and misoperations in the volume operation can be avoided. That is, the system environment of the volume operation can avoid corruption. 
         [0094]    At step  907 , after the completion of step  906 , that is, after the requested storage setup is completed, the status of the volume is obtained again. At this time, the pair and guard operations may change the volume status, which should be confirmed as with step  907 . This step may be omitted for the path operation that involves no change of the volume status. However, the process of step  907  may be required for a path operation that manages the volume status such as the status of “PATH” or “NO PATH”, which affects the shared volume operation. After the process of step  907  is completed, the process continues to step  908 . 
         [0095]    For example, suppose that a user having user ID “1” in the user management table  310  executes an operation of changing the status “PAIRING” of the pair of “VOL1” and “VOL2” indicated in the pair management table  220  to the status “PAIR SPLIT”. In this case, the pair operation at step  906  changes the status of the pair of “VOL1” and “VOL2” to “PAIR SPLIT”. This status is obtained at step  907 . The guard status is not changed and remains to be “NOT GUARDED”. The process then continues to step  908 . 
         [0096]    At step  908 , it is determined whether there is any resource of other users that requires dynamic setup, that is, whether any task of other users includes an operation having “YES” in dynamic setup  504  of the shared volume operation management table  500 . If there is any volume of other users that has “YES” in dynamic setup  504 , the process continues to step  909 . Otherwise, the process continues to step  910 . 
         [0097]    For example, suppose that a user having user ID “1” in the user management table  310  executes an operation of changing the status “PAIRING” of the pair of “VOL1” and “VOL2” indicated in the pair management table  220  to the status “PAIR SPLIT”. In this case, the pair operation at step  906  changes the status of the pair of “VOL1” and “VOL2” to “PAIR SPLIT”. Suppose further that backup permission is granted to the volume of the replication destination simultaneously with the above pair operation. That is, suppose that in a backup process, a backup server (host) is used to transfer data of the replication destination volume to the volume of the backup destination. In this case, “VOL2” is the replication destination volume of the pair operation, and has a status of “BACKUP PERMITTED”. This status is obtained at step  907 . The guard status is not changed and remains to be “NOT GUARDED”. 
         [0098]    In this case, “VOL2” is shared with the user having user ID “2” in the user management table  310  and being responsible for the backup task. In addition, it is determined from the shared volume operation management table  500  that dynamic setup  504  has a value of “YES” in the backup task having the status of “PAIR SPLIT” and “BACKUP PERMITTED”. At this time in the process, the operation by the user of the backup task is automatically executed. Therefore, in this case, the process continues to step  909 . 
         [0099]    At step  909 , storage setup is executed on the resources intended for dynamic setup. After the storage setup is completed, the process continues to step  910 . 
         [0100]    For example, referring to the example at step  908 , the volume “VOL2” served as a shared volume is subjected to dynamic setup for the path operation, where a path is set up for port “PORT-A1” and host “HOST-B” to be connected with “VOL2”. If this path has already been set up, it is not necessary to execute this setup, and confirmation of this path may be executed. Here, a path operation may imply path setup between a port and a volume in the storage. Alternatively, in order to actually execute the backup process by a host, a series of processes starting from the above-described path setup until a volume is mounted from the host may be defined as a path setup, and its path environment may be constructed. If a volume of replication destination is mounted during pairing, there is a danger that data is written into the volume of replication destination, which may cause difficulty in synchronizing data between the volume of replication source and the volume of replication destination. For this reason, the processes up to mounting may be executed in the backup task. 
         [0101]    In the above process, the definition of a path for “VOL2” can be uniquely derived from the managed resource of the user having user ID “2”. However, there may be a plurality of options depending on the assignment of managed resources. The options may include a setting that should be actually set up and another setting that should not be set up. In this case, a path to be set up may be predetermined for each shared resource. 
         [0102]    At step  910 , it is determined whether resources of other users are delegated, that is, whether resources associated with the volume shared with other users are delegated according to the status of the volume, or in other words, whether there is any operation having resource delegation  505  ( 705 ) of “YES” in the shared volume operation management table  500  ( 700 ) in the task of other users. If there is any resource delegation, the process continues to step  911 . Otherwise, the process is terminated. 
         [0103]    For example, guard setup executed on the managed resource “VOL1” by the user having user ID “3” in the user management table  310  changes the status of “VOL1” to “GUARDED”. At this time, in the shared volume operation management table  500 , resource delegation  505  is “YES” for “GUARDED” path and pair operations. This means that the resources of the user having user ID “1” responsible for tasks for operating paths or pairs in “VOL1”, that is, storage tasks in this case, are delegated. Therefore, in this case, the process continues to step  911 . 
         [0104]    In addition, for example, pair setup executed on the managed resource “VOL1” by the user having user ID “12” in the user management table  410  changes the status of “VOL1” to “PAIRING”. At this time, in the shared volume operation management table  700 , resource delegation  705  is “YES” for “PAIRING” or “PAIRED” path operation. This means that the resources of the user having user ID “11” responsible for tasks for operating paths in “VOL1”, that is, path tasks in this case, are delegated. Therefore, in this case, the process continues to step  911 . 
         [0105]    At step  911 , it is directed that the resources intended for delegation be treated as managed resources of the delegate user. The process is then terminated. 
         [0106]    For example, referring to the example at step  910 , the volume “VOL1” owned by user ID “1” and shared with user ID “3”, as well as the resources of volumes, ports, and hosts used by paths and pairs already set up in the storage task, are delegated. This status is maintained by the managing server, which responds to the delegate user by directing the user to treat the resources as managed resources. 
         [0107]    In addition, for example, referring again to the example at step  910 , the volume “VOL1” owned by user ID “11” and shared with user ID “12”, as well as the resources of volumes, ports, and hosts used by paths already set up in the storage task, are delegated. This status is maintained by the managing server, which responds to the delegate user by directing the user to treat the resources as managed resources. 
         [0108]    Accordingly, in the shared volume subjected to guard setup, the operation authority over the volume having guard setup is delegated to a user of the guard task, and operations by other users can be excluded. 
         [0109]    At step  912 , a process of returning the cause of the error as an error message is carried out in order to communicate the error to the user. 
         [0110]    In this way, the volume operation authority of other users can be coordinated in response to the request of a user. Influence of the operation by other users can be excluded, and misoperations in the volume operation can be avoided. That is, the system environment of the volume operation can avoid corruption. 
         [0111]    Moreover, volume operations may include operations executed from the storage coordination program  104  of the managing computer  100  and operations executed from the storage coordination program  115  of the host  110 , where some of the operations may be in common. In this case, if one storage coordination program operates on a volume while the other storage coordination program operates on the same volume, these volume operations will lose consistency. In such a case, when one storage coordination program is operating, the operation authority of the other storage coordination program can be coordinated to inhibit its operation. 
         [0112]    Furthermore, the volumes having the status “NOT PAIRED” for pair operation may include volumes that have never been involved in creation of a pair and volumes that have been involved in pair setup followed by pair deletion. Depending on the implementation, these two types of volumes may be separated. For example, if a user of the backup task at the managing computer distinguishes the “NOT PAIRED” status in which pair setup is followed by pair deletion, the backup data can still be read out of the associated volume, and thus the operation on the volume may be allowed. If the volume has a status of “PAIRING” again, it will be treated as having no authority. 
         [0113]    As with the path setup process, the function of limiting hosts capable of using the path (hereinafter referred to as “path security function”) is also delegated in the same manner as delegation of the path setup operation, thereby achieving consistency of the volume operation. 
         [0114]    Various programs and information in the managing computer  100  may be contained either in the storage  120  or in the host  110 . 
         [0115]      FIG. 10  is an example illustrating a display screen that displays to a user the volumes managed by the user that allow operation. 
         [0116]    User volume operation confirmation screen  1000  provides display items including user type  1001 , managed volume  1002  displaying the volume managed by the user, and operation availability  1003  indicating whether the volume managed by the user allows operation. 
         [0117]    The user type displays a user and a task stored in the user management table  310  or  410 . It provides display for each user when the user presents a display request to the managing computer. 
         [0118]    The managed volume  1002  is directed to the volumes of the managed resources stored in the user management table  310  or  410 . 
         [0119]    The operation availability  1003  indicates whether the intended operation is available for the managed volume  1002 . 
         [0120]    For example, as already illustrated in the example of  FIG. 9 , the user having user ID “1” is responsible for the storage task and executes the path and pair operations. However, if there is any volume shared with other users, the path or pair operation for executing the storage task may be prohibited depending on the status of the volume, so that the operation availability of the shared volume may be “PATH OPERATION UNAVAILABLE” or “PAIR OPERATION UNAVAILABLE”. For example, as already illustrated in the example of  FIG. 9 , “VOL2” is shared with the user having user ID “2” responsible for the backup task. In this case, if the status of the volume is “PAIR SPLIT, BACKUP PERMITTED, NOT GUARDED”, then it is determined from the shared volume operation management table  500  that the user having user ID “1” is responsible for the storage task and has no operation authority over path and pair operations. Therefore, in this case, “PATH OPERATION UNAVAILABLE” and “PAIR OPERATION UNAVAILABLE” are displayed. 
         [0121]    The above-described user volume operation confirmation screen  1000  may be displayed to each user so that it can be determined whether the operation authority of each user is available. 
         [0122]    In the user volume operation confirmation screen, the managed volume  1002  may display the indication of the shared volume. The operation availability may be displayed only for shared volumes. The status of the volume may also be shown. 
       Second Embodiment 
       [0123]    The second embodiment will now be described.  FIG. 11  shows the configuration of a computer system in the second embodiment of the invention. A switch  1100  is added to the computer system of the first embodiment shown in  FIG. 1 . The switch  1100  is connected with the storages  120 , hosts  110 , and managing computer  100  for passing data among them. The switch  1100  comprises interfaces (I/F)  1102  for communicating with the storage  120 , host  110 , managing computer  100 , and the like, a CPU  1101  for actually controlling the switch, and a memory  1103 . The interfaces  1102  may include separate communication devices for different forms of communication (e.g., IP (Internet Protocol) for communication with the managing computer and FC (Fibre Channel) for data I/O). The memory  1103  contains a switch configuration program  1104 , which is embodied by being executed by the CPU  1101 . The switch configuration program  1104  is a program for managing the configuration of the switch  1100 , and has a function of determining which of the interfaces  1102  to use for communication (hereinafter referred to as “switch path setup function”) and the like. 
         [0124]    The managing computer  100  further includes a switch coordination program  1110  for coordinating with the switch  1100 . The switch coordination program  1110  is used to obtain information and issue a setup request. 
         [0125]    In view of the presence of control by the switch  1100 , the path operation for the storage should be executed with the switch path setup function of the switch  1100  taken into consideration. That is, when the host  110  writes data into the volume  125  of the storage  120 , the data I/O flows via the switch  1100 . Therefore the managing computer  100  needs to direct the switch configuration program  1104  of the switch  1100  via the switch coordination program  1110  to ensure a data path so that data can flow between the host  110  and the storage  120 . 
         [0126]    In addition, as described above, depending on the task, the authority for path setup may need to be delegated by the user of another task. In this case, the operation authority over the switch as well as the operation authority of the path setup for the storage should be delegated. However, since the path of the switch may be shared, confirmation of the authority rather than delegation thereof may be executed in the path task. 
         [0127]    Moreover, encryption equipment  1120  is added to the computer system shown in  FIG. 1 . The encryption equipment is connected with the storages  120 , hosts  110 , and managing computer  100 , although via the switch  1100 . The encryption equipment has a function of encrypting data to be written into the volume  125  of the storage  120  by the host  110  and decrypting data so that the host  110  can normally view it. The encryption equipment  1120  comprises an interface  1122  for communicating with the storage  120 , host  110 , managing computer  100 , and the like, a CPU  1121  for actually controlling encryption and decryption, and a memory  1123 . The interface  1122  may include separate communication devices for different forms of communication (e.g., IP (Internet Protocol) for communication with the managing computer and FC (Fibre Channel) for data I/O). The memory  1123  contains an encryption/decryption program  1124 , which is embodied by being executed by the CPU  1121 . The encryption/decryption program  1124  is a program for encrypting and decrypting data. 
         [0128]    The managing computer  100  further includes an encryption equipment coordination program  1130  for coordinating with the encryption equipment  1120 . The encryption equipment coordination program  1130  is used to obtain information and issue a setup request. 
         [0129]    In view of the presence of control by the encryption equipment  1120 , data may be encrypted in the volume  125  of the storage  120 . When the encrypted volume is shared by a plurality of users, the user that executed the encryption may be allowed to manage the shared volume to avoid misoperation by the other users. In this case, a certain definition similar to the guard setup may be provided in the shared volume operation management table  500 . 
         [0130]    In this way, both in a storage configuration including a switch and in a storage configuration including encryption equipment, the volume operation authority of other users can be coordinated in response to the request of a user. Influence of the operation by other users can be excluded, and misoperations in the volume operation can be avoided. That is, the system environment of the volume operation can avoid corruption. 
         [0131]    The invention has been described with reference to the embodiments. In an aspect of the computer system of the invention, upon obtaining the operation content of one user for at least one of the volumes over which two or more users have the operation authority, the managing computer determines from the attribute of the volume and the operation authority of the two or more users over the volume whether the operation content is executable, and when the operation content is executable, the operation authority of the other users over the volume is changed depending on the attribute of the volume. 
         [0132]    In another aspect of the computer system of the invention, when the managing computer determines whether the operation content for the volume is executable, the host computer used by the one user displays whether the operation on the volume is available. 
         [0133]    In still another aspect of the computer system of the invention, when one user executes an operation on at least one of the volumes over which two or more users have the operation authority, the managing computer obtains the attribute of the volume after the execution of the volume operation and, according to the obtained attribute of the volume, determines whether the volume operation of other users is to be executed, and when there is no setup for the volume operation of the one user, the volume operation of the other users is executed. 
         [0134]    In still another aspect of the computer system of the invention, when one user executes an operation on at least one of the volumes over which two or more users have the operation authority, the managing computer obtains the attribute of the volume after the execution of the volume operation and, according to the obtained attribute of the volume, delegates the operation authority of other users over the at least one volume to the one user. 
         [0135]    In still another aspect of the computer system of the invention, the managing computer treats a process of causing the host computer controlling the volume to recognize the volume as being covered by the operation authority of the user. 
         [0136]    In still another aspect of the computer system of the invention, the managing computer selects a replication source volume and a replication destination volume from a plurality of volumes, and treats a process of replication from the replication source volume to the replication destination volume as being covered by the operation authority of the user and treats a status of the replication process as the attribute of the volume. 
         [0137]    In still another aspect of the computer system of the invention, the managing computer treats a process of write protection or read protection of the volume from the computer controlling the volume as being covered by the operation authority of the user and treats a status of the write protection or the read protection as the attribute of the volume. 
         [0138]    In still another aspect of the computer system of the invention, the managing computer treats a process of encrypting data in the volume as being covered by the operation authority of the user and treats a status of the data in the volume being encrypted as the attribute of the volume. 
         [0139]    In still another aspect of the computer system of the invention, the managing computer has a memory storing a storage coordination program, a volume authority management program, a host coordination program, storage management information, and task management information including a task operation table and a user management table, the host computer has a memory storing a task program, a storage coordination program, and a managing computer coordination program, the storage has a memory storing a storage configuration program, and the managing computer is operative for: using the task operation table and the user management table to determine whether a storage setup request received from the user is within the task and a managed resource of the user, and whether the pertinent volume is shared with other users; when the request is within the task and managed resource of the user but the volume is shared with the other users, determining whether the volume to be set up allows operation in the status of the volume; when the operation is allowed, executing storage setup associated with the storage setup request received from the user; obtaining the status of the managed resource again; determining whether need for dynamic setup for the other users exists; when the need exists, executing storage setup for the resource intended for the dynamic setup; determining whether the resource of other users is delegated; and when the resource of the other users is delegated, directing the intended resource to be treated as the managed resource. 
         [0140]    The invention is also directed to a managing computer for managing at least one storage having one or more volumes served as a storage region, the storage being connected via a network, two or more users being capable of obtaining an operation authority over an identical volume, wherein upon obtaining an operation content in a host computer managed by one user for at least one of the volumes over which two or more users have the operation authority, the managing computer determines from an attribute of the volume and the operation authority of the two or more users over the volume whether the operation content is executable, and when the operation content is not executable, the operation content is restrained. 
         [0141]    The invention is also directed to a host computer managed by a user capable of obtaining and managing an operation authority over an identical volume in a storage with other users, the storage having one or more volumes served as a storage region, wherein when the user executes an operation on the volume in the storage, and when a managing computer for managing the storage determines from an attribute of the volume and the operation authority of two or more users over the volume whether the operation content is executable, the host computer displays whether the operation on the volume is available. 
         [0142]    The invention is also directed to a storage comprising one or more volumes served as a storage region, a plurality of users being capable of obtaining an operation authority over at least one of the volumes, wherein when a managing computer determines that an operation content of one user for at least one of the volumes over which two or more users have the operation authority is not executable from an attribute of the volume and the operation authority of the two or more users over the volume, the operation content is prevented from being executed. 
         [0143]    The invention is also directed to a volume management method in a computer system including at least one storage having one or more volumes served as a storage region, a managing computer for managing the storage, and a plurality of host computers, each host computer being used by a user capable of obtaining an operation authority over the volume in the storage, where the storage, the managing computer, and the host computers being interconnected via a network, and two or more users being capable of using an identical volume, the method comprising the steps of: obtaining an operation content in the host computer used by one user for the volume; determining whether the one user has the operation authority over the volume; determining whether other users have the operation authority over the volume; obtaining an attribute of the volume; obtaining the operation authority of the other users over the volume; determining from the attribute of the volume and the operation authority of the other users over the volume whether the operation content is executable; and when the operation content is not executable, restraining the operation content. 
         [0144]    In an aspect of the volume management method of the invention, the method further comprises the step of: when the operation content is executable, changing the operation authority of the other users over the volume depending on the attribute of the volume. 
         [0145]    In another aspect of the volume management method of the invention, the method further comprises the step of: upon determining whether the operation content for the volume is executable, displaying whether the operation on the volume is available. 
         [0146]    In still another aspect of the volume management method of the invention, the method further comprises the steps of: upon execution of an operation by one user on at least one of the volumes over which two or more users have the operation authority, obtaining the attribute of the volume after the execution of the volume operation; according to the obtained attribute of the volume, determining whether the volume operation of other users is to be executed; and when there is no setup for the volume operation of the one user, executing the volume operation of the other users. 
         [0147]    In still another aspect of the volume management method of the invention, the method further comprises the steps of: upon execution of an operation by one user on at least one of the volumes over which two or more users have the operation authority, obtaining the attribute of the volume after the execution of the volume operation; and according to the obtained attribute of the volume, delegating the operation authority of other users over the at least one volume to the one user. 
         [0148]    In still another aspect of the volume management method of the invention, a process of causing the host computer controlling the volume to recognize the volume is treated as being covered by the operation authority of the user, and a process of executing setup for writing data into the volume or reading data from the volume by the host computer is treated as being covered by the operation authority of the user. 
         [0149]    In still another aspect of the volume management method of the invention, a replication source volume and a replication destination volume is selected from a plurality of volumes, a process of replication from the replication source volume to the replication destination volume is treated as being covered by the operation authority of the user, and a status of the replication process is treated as the attribute of the volume.