Abstract: A storage network system that can be kept running despite a failure in a host computer is provided. A computer system includes: first, second and third storage systems which store data and are connected to one another; a primary host computer connected to the first storage system; a secondary host computer connected to the second storage system; and a management portion which manages data transfer between the storage systems, in which the management portion sets the storage systems such that, while the primary host computer is in operation, data stored in the first storage system is transferred to the second storage system and data stored in the second storage system is transferred to the third storage system, and wherein the management portion sets the storage systems such that, while the secondary host computer is in operation, data stored in the second storage system is transferred to the first storage system and data stored in the first storage system is transferred to the third storage system.

Abstract: When collecting information about management of a storage of a disk subsystem, loads imposed on a host computer and a network are alleviated to improve the throughput of a computer system having the storage. The disk subsystem includes a CPU and a main memory and information on a disk is collected in response to a request from a management computer. An information collection program is operated on the disk subsystem, whereby, volume management information can be edited on the disk subsystem and utilized by the management computer.

Abstract: In a computer system, to enable a second computer to take over control of copying of data within the computer system, from a first computer that normally controls copying of data. The second computer selects from a plurality of storage systems a storage system to be accessed in order to acquire sub system pair information, and acquires sub system pair information from the selected storage system. Based on the acquired sub system pair information, the second computer generates system pair information that includes copy pair information relating to a plurality of storage areas belonging to the plurality of storage systems. The second computer initially selects a storage system directly linked to the second computer, and subsequently sequentially selects a storage system based on the acquired sub system pair information.

Abstract: Transfer of data and replication of data among several storage devices are executed without imposing a load on the computer connected to the storage system. For example, a first host computer monitors usage rates of transfer groups TG11, TG12 and physical path usage rate on a storage device interconnect physical path 50, and when either a usage rate or physical path usage rate goes above a predetermined value, issues to the first storage device 20 an instruction to allocate a reserved volume R11, R12. The first host adaptor 21 receiving the reserved volume R11, R12 allocation request allocates reserved volume R11 to transfer group TG1, whereby a virtual transfer volume is formed by transfer volume T11 and the reserved volume R11 allocated thereto. As a result, capacity of the virtual transfer volume is increased by the equivalent of the reserved volume R11 capacity, so that additional transfer frames may be stored.

Abstract: To provide a computer system capable of detecting a failure at an early stage while keeping down an increase in I/O load due to failure monitoring. The computer system includes plural storage systems connected in stages between a first computer and a second computer. The first computer sends control I/O to the storage systems. The second computer monitors control I/O transferred through the storage systems; and when there is control I/O that has not been transferred successfully, requests state information of the storage systems to transfer the control I/O.

Abstract: In order to solve problems that, when the use area used by data of a certain kind reaches the upper limit value, the cache memory cannot be used even though a space area exists in the use area used by data of other kind and utilization efficiency of the cache memory decreases, and that, when the upper limit value of the use area is discarded, on the other hand, data inside the area held is replaced by other data and disappears, a storage area of a size of a minimum guarantee value corresponding to each computer is set inside a disk cache memory in a control device of a storage device connected to a plurality of computers and a storage area is allocated to each computer in accordance with priority corresponding to each computer.

Abstract: The computer system comprises a first and second computer, at least one first storage system connected to the first computer, and a plurality of second storage systems connected to the second computer as well as being connected to the at least one first storage system. The first computer issues to the first storage system a normal write request and control-use write request stamped with issue time. A control-use write request is issued at periodic intervals. The first storage system receives a write request and transmits the write request as update-data to second storage system in such a way that the issue order is ascertainable. The second storage system receives the update-data and, responsive to a reflect instruction from the second computer, reflects the update-data in storage areas.

Abstract: Transfer of data and replication of data among several storage devices are executed without imposing a load on the computer connected to the storage system. For example, a first host computer monitors usage rates of transfer groups TG11, TG12 and physical path usage rate on a storage device interconnect physical path 50, and when either a usage rate or physical path usage rate goes above a predetermined value, issues to the first storage device 20 an instruction to allocate a reserved volume Ri 1, R12. The first host adaptor 21 receiving the reserved volume Rh, R12 allocation request allocates reserved volume Ru to transfer group TGI, whereby a virtual transfer volume is formed by transfer volume Til and the reserved volume Ru allocated thereto. As a result, capacity of the virtual transfer volume is increased by the equivalent of the reserved volume Ru capacity, so that additional transfer frames may be stored.

Abstract: A storage system is disclosed comprising a management computer and multiple storage subsystems with multiple volumes accessible to a host computer. The host computer sends volume configuration information to the management computer. Each storage subsystem retrieves information from the volume directory corresponding to a requested volume and sends it to the management computer. The management computer comprises a volume information table holding the volume configuration information obtained from the host computer, information on storage subsystems, and use-related ID group IDs; a unit which identifies the volumes belonging to a specified group ID, locates the storage subsystems these volumes belong to, and obtains information on the desired volumes from their corresponding volume directories; and a display device which displays information on the usage of the volumes that is obtained from storage subsystems.

Abstract: In a computer system with a plurality of levels of cache storage, a cache control method prevents data duplication among the levels of cache storage to increase cache storage utilization. A high-level cache staging unit stages reads data from a disk unit, stages the data to a high-level cache, and instructs to destage the data, which has been read, from a low-level cache. A high-level cache destaging unit writes data to be destaged to the disk unit, instructs to stage the data, which has been written, to the low-level cache, and destages the data from the high-level cache. A low-level cache staging unit stages a data, which is written by the high-level cache destaging unit, to the low-level cache. A low-level cache destaging unit destages a data, which is instructed by the high-level cache staging unit, from the low-level cache.

Abstract: An object of the present invention is to intensity protection of data in a disk device that is shared by a plurality of computers or a plurality of programs. According to the present invention, a connection control program handles input or output from or to a logical volume. An input/output execution control block references a connection information definition block to retrieve a connected state value concerning the connection of an input/output request source computer to an object logical volume or an object logical area. The input/output execution control block then judges whether input or output from or to the logical volume or logical area is enabled. If input or output is enabled, input or output from or to the object logical volume or logical area is executed. If input or output is disabled, input or output is not executed.

Abstract: A computer system having a plurality of host computers and a storage system is provided which allows any one host computer to perform a global copy operation on any arbitrary or all storage areas in the storage system. To this end, storage areas provided by the disk devices are grouped into groups by allocating group numbers to a plurality of specified storage areas. The copy operation can be performed by specifying desired groups. Each of the groups is made up of sub-groups and the sub-groups are defined for each computer to assure a consistency of copy order of the sub-groups.

Abstract: A computer system includes a host computer, a disk control device controlling operation of a storage sub-system, and a management server managing configuration of the storage sub-system. The host computer registers the result of grouping of a plurality or volumes in the storage sub-system according to a use purpose in a volume management table including a volume identifier, a physical address, and a group identifier allocated in the disk control unit. During access to the volume via the host, the disk control unit obtains the physical address belonging to a storage belonging to a group identical to the group input via the host, notifies information described on the volume list of the storage allocated at the physical address to the management server, and causes the server to display the information.

Abstract: A processing unit (processor) performs processing of programs. A monitoring unit measures the rate of operation of an instruction processor in the processing unit. Information which is a standard for judging modification of the performance is stored in a control information memory unit. A control unit judges on the basis of the operation rate of the processor collected by the monitoring unit and the control information stored in the control information memory unit whether it is necessary to modify the performance or not and controls to modify the performance of the processor on the basis of the judged result.

Abstract: When collecting information about management of a storage of a disk subsystem, loads imposed on a host computer and a network are alleviated to improve the throughput of a computer system having the storage. The disk subsystem includes a CPU and a main memory and information on a disk is collected in response to a request from a management computer. An information collection program is operated on the disk subsystem, whereby, volume management information can be edited on the disk subsystem and utilized by the management computer.

Abstract: A processing unit (processor) performs processing of programs. A monitoring unit measures the rate of operation of an instruction processor in the processing unit. Information which is a standard for judging modification of the performance is stored in a control information memory unit. A control unit judges on the basis of the operation rate of the processor collected by the monitoring unit and the control information stored in the control information memory unit whether it is necessary to modify the performance or not and controls to modify the performance of the processor on the basis of the judged result.

Abstract: In a computer system with a plurality of levels of cache storage, a cache control method prevents data duplication among the levels of cache storage to increase cache storage utilization. A high-level cache staging unit stages reads data from a disk unit, stages the data to a high-level cache, and instructs to destage the data, which has been read, from a low-level cache. A high-level cache destaging unit writes data to be destaged to the disk unit, instructs to stage the data, which has been written, to the low-level cache, and destages the data from the high-level cache. A low-level cache staging unit stages a data, which is written by the high-level cache destaging unit, to the low-level cache. A low-level cache destaging unit destages a data, which is instructed by the high-level cache staging unit, from the low-level cache.

Abstract: A processing unit (processor) performs processing of programs. A monitoring unit measures the rate of operation of an instruction processor in the processing unit. Information which is a standard for judging modification of the performance is stored in a control information memory unit. A control unit judges on the basis of the operation rate of the processor collected by the monitoring unit and the control information stored in the control information memory unit whether it is necessary to modify the performance or not and controls to modify the performance of the processor on the basis of the judged result.

Abstract: A method, apparatus and computer program which allows the simultaneous execution of an application that requires input/output of static data not modified by another application after a particularly point in time and another application. The invention provides static data controller which determines whether an application has issued a data input/output request. The static data controller sends the data input/output request issued by the application requiring input/output of static data not modified by another application after a particular point in time to a first external storage device and a data input/output request issued by any other application to a second external storage device.