Abstract: A system includes at least a user and a file system connected to the user through a network. An estimated write size of a write operation of the user into the file system is managed as an accumulated value. The timing of judging the limit of the disk usage amount is specified from the accumulated value and a predetermined threshold value, and the limit of the disk usage amount is judged at the specified timing, so that disk usage amount by a user may be limited and managed.

Abstract: A method for moving files between network storages in a virtualized network storage system having multiple network storages and rebalancing the free disk spaces. It periodically judges whether to start rebalancing. Two different conditions are adopted for the determination of start: (a) an imbalance of free disk spaces and the minimum value of the free disk spaces is less than a threshold and (b) an imbalance of free disk spaces and the frequency of accesses to the system is less than a threshold. Rebalancing is performed until the difference in free disk spaces falls below the threshold without exceeding the maximum execution time of rebalancing. If a request to write into a file which is being moved from a client takes place during a file moving step, the movement of the file is aborted and the file is deleted from the destination.

Abstract: There are provided a heap memory management method that not only improves processing performance of an application program but also reduces a program development cost and a computer system using the same method. A live object copy process in minor collection of generational garbage collection is implemented through a calculate process of object live ratio, a compare process of object live ratio, and a live object copy process. The calculate process of object live ratio calculates a ratio of a size of a memory allocated to live objects of new objects to a size of a memory allocated to a new object during minor collection. The compare process of object live ratio compares a calculated object live ratio with a predetermined threshold. The live object copy process copies a live object directly to an old-generation heap instead of a new-generation heap when the object live ratio exceeds the threshold as a result of comparison.

Abstract: A technique to replace components adaptively to a sign of imminent failure or actual failure without allowing error or deterioration in performance to occur at the time of replacing components is described. A technique to have new requests directed to the replaced components executed by the new components is also described.

Abstract: Disclosed are a virtual computer system and method, wherein computer resources are automatically and optimally allocated to logical partitions according to loads to be accomplished by operating systems in the logical partitions and setting information based on a knowledge of workloads that run on the operating systems. Load measuring modules are installed on the operating systems in order to measure the loads to be accomplished by the operating systems. A manager designates the knowledge concerning the workloads on the operating systems through a user interface. An adaptive control module determines the allocation rations of the computer resources relative to the logical partitions according to the loads and the settings, and issues an allocation varying instruction to a hypervisor so as to thus instruct variation of allocations.

Abstract: A method for moving files between network storages in a virtualized network storage system having multiple network storages and rebalancing the free disk spaces. It periodically judges whether to start rebalancing. Two different conditions are adopted for the determination of start: (a) an imbalance of free disk spaces and the minimum value of the free disk spaces is less than a threshold and (b) an imbalance of free disk spaces and the frequency of accesses to the system is less than a threshold. Rebalancing is performed until the difference in free disk spaces falls below the threshold without exceeding the maximum execution time of rebalancing. If a request to write into a file which is being moved from a client takes place during a file moving step, the movement of the file is aborted and the file is deleted from the destination.

Abstract: A system includes at least a user and a file system connected to the user through a network. An estimated write size of a write operation of the user into the file system is managed as an accumulated value. The timing of judging the limit of the disk usage amount is specified from the accumulated value and a predetermined threshold value, and the limit of the disk usage amount is judged at the specified timing, so that disk usage amount by a user may be limited and managed.

Abstract: A data transfer method realizing a function similar to Unix's FORK by the following operations: allowing a parent process on a server to issue a request for intermission of communication to a process on a client and allowing the process on the client to issue a report of completion of intermission; allowing the parent process to issue, to a child process created on the server and the process on the client, a request for establishment of a new communication line connection between them; and, if the parent process has received data from the process on the client before the establishment of the new connection, coping the data to the child process.

Abstract: Disclosed are a virtual computer system and method, wherein computer resources are automatically and optimally allocated to logical partitions according to loads to be accomplished by operating systems in the logical partitions and setting information based on a knowledge of workloads that run on the operating systems. Load measuring modules are installed on the operating systems in order to measure the loads to be accomplished by the operating systems. A manager designates the knowledge concerning the workloads on the operating systems through a user interface. An adaptive control module determines the alalocation ratios of the computer resources relative to the logical partitions according to the loads and the settings, and issues an allocation varying instruction to a hypervisor so as to thus instruct variation of allocations.

Abstract: A computer resource marketing system using LPAR (logical partitioning) technology that divides a computer resource into a plurality of logical partitions, including a lending server with a logical partition control unit 3 that designates at least one logical partition as a lendable partition, a client system that can borrow a logical partition in the lending server and submit processing to the logical partition, a resource database that stores lending conditions and certification information of logical partitions in the lending server, and a management server that searches the resource database based on a borrowing request from a client system, notifies the client system of a logical partition that meets the requirements of the borrowing request, and authorizes the client system to use the logical partition.

Abstract: A system having at least a user and a file system connected to the user through a network is disclosed, in which an estimated write size of the user into the file system is managed as an accumulated value, the timing of judging the limit of the disk usage amount is specified from the accumulated value and a predetermined threshold value, and the limit of the disk usage amount is judged at the specified timing.

Abstract: A file replication method which allows, between a plurality of virtualized-and-unified file systems, real-time creation of a partial copy of that one of the virtualized-and-unified file systems as a target of replication is provided. The replication-source virtualized-and-unified file system is provided with a unified management directory for managing a structure of files and directories and the attribute information thereof, replication information for setting the file as an object to be copied, a request reception unit for receiving a request from a client in a unified manner, and a replication unit for judging whether or not replication should be performed in accordance with the unified management directory and the replication information and simultaneously transferring, based on the result of the judgment, the file access request to the replication-source virtualized-and-unified file system and to the replication-destination virtualized-and-unified file system.

Abstract: A cache coherence control system for a multi CPU system having a plurality of CPU nodes, memory nodes and I/O nodes interconnected by a network. Each CPU node control circuit has an access right memory for managing an access right of the node in the unit of an extended node larger than a block size of the internal cache of a CPU. When a memory access is performed, the access right memory is referred to, and if the node has an access right to the extended block including a target block, the block is accessed without cache coherence control at other nodes.

Abstract: A method for moving files between network storages in a virtualized network storage system having multiple network storages and thereby rebalancing the free disk spaces therein. It periodically judges whether to start rebalancing. Two different conditions are adopted for the determination of start: (a) there is an imbalance of free disk spaces and the minimum value of the free disk spaces is less than a threshold and (b) there is an imbalance of free disk spaces and the frequency of accesses to the system is less than a threshold. Rebalancing is carried out until the difference in free disk spaces falls below the threshold to the extend that the maximum execution time of rebalancing will not be exceeded. If a request to write into a file which is being moved from a client takes place during a file moving step, the movement of the file is aborted and the file is deleted from the destination thereof. Then, another file is selected and the file moving step is carried out again.

Abstract: A system and method for virtualizing a new network storage additionally installed and an existing network storage as a single file system by inheriting a directories tree structure from the existing network storage, wherein a virtualizing system of the new network storage has the function of reading out setup information of the existing network storage according to an expansion request from the administrator, registering the existing network storage as a member of the virtualizing system, copying a directories tree structure of the existing network storage, and swapping setup information of the existing network storage and that of he new network storage with each other.

Abstract: A virtualizing file system view method for virtualizing one or more network storage devices into a virtualized file system view network storage system wherein destination network storage information of stored files is compactly held regardless of the number of files, and files are separated into one or more file groups and the file groups managed in destination network storage units. Until now, managing network storage unit information in individual files was necessary however the virtualizing file system view method reduces the management information that must be held and efficiently utilizes network storage capacity without holding destination network storage information in individual files. The cost of rewriting information is also lowered during structural changes such as adding or deleting network storage units since storage destination network information can be rewritten in file groups.

Abstract: There are provided a heap memory management method that not only improves processing performance of an application program but also reduces a program development cost and a computer system using the same method. A live object copy process in minor collection of generational garbage collection is implemented through a calculate process of object live ratio, a compare process of object live ratio, and a live object copy process. The calculate process of object live ratio calculates a ratio of a size of a memory allocated to live objects of new objects to a size of a memory allocated to a new object during minor collection. The compare process of object live ratio compares a calculated object live ratio with a predetermined threshold. The live object copy process copies a live object directly to an old-generation heap instead of a new-generation heap when the object live ratio exceeds the threshold as a result of comparison.

Abstract: A cache memory unit that preferentially stores specific lines at the cache memory, according to the program nature, dynamically changes the priority ranks of lines, and increases the cache memory hit rate. For this purpose, the lines to be accessed by a processor are divided into groups and definitions of the groups are set in a group definition table; a policy by which to store lines belonging to the groups into the cache memory is set in a policy table; and storing lines into the cache memory is executed, according to the group definitions and the policy of storing set in the tables.

Abstract: A multiprocessor system can reduce a broadcast for cache memory consistency control with memory access from an I/O device. The multiprocessor system is provided with a cache memory identifier or an owner tag, and a block length table for recording a memory write block length of the I/O device. The cache memory identifier records that the cache has an exclusive copy. The owner tag records that there is no cache memory having an exclusive copy. If there is an exclusive copy during read through the I/O device, a read request is issued to both a cache holding the copy and a memory. If it is recorded that the copy is not present, data are directly read from the memory. Moreover, when a write block length is recorded in the block length table during write, whole blocks are collected to issue a request for invalidation from the cache and the request is directly written to the memory after the invalidation is completed.

Abstract: Disclosed are a virtual computer system and method, wherein computer resources are automatically and optimally allocated to logical partitions according to loads to be accomplished by operating systems in the logical partitions and setting information based on a knowledge of workloads that run on the operating systems. Load measuring modules are installed on the operating systems in order to measure the loads to be accomplished by the operating systems. A manager designates the knowledge concerning the workloads on the operating systems through a user interface. An adaptive control module determines the alalocation ratios of the computer resources relative to the logical partitions according to the loads and the settings, and issues an allocation varying instruction to a hypervisor so as to thus instruct variation of allocations.