Abstract: To solve a problem of waste of management resources/wasteful management involved in the setting of information defining access rights of multiple users to a single file and the setting of differing file attributes information for each file, this system has a file attributes DB operating as a database managing file attributes, a accounting information DB as a database managing accounting information and a local file system storing file data. The accounting information DB holds records for each combination of a user or group and a server and adds records for each additional user or server.

Abstract: A magnetic head for use in the vicinity of a magnetic recording medium, comprising a substrate, a close contact layer laminated on the substrate, and a protective layer which is laminated on the close contact layer and which faces the magnetic recording medium, the protective layer comprising a first layer formed by laminating a laminate material on the close contact layer at a first bias voltage by a filtered cathodic vacuum arc (FCVA) process, and a second layer formed by laminating the laminate material on the first layer by the FCVA process at a second bias voltage which is higher than the first bias voltage.

Abstract: To provide an atomic force microscopy which allows the measurement of the configuration of a surface being measured by using the phenomenon observed between the surface being measured and a probe approaching thereto at very fine distance. By selecting the material of the tip surface of said probe such that the surface energy of said probe tip becomes less than the interface energy between the tip surface and the surface being measured, thereby the surface configuration of soft body, or soft fouling adhered to the body surface can be measured. A method of measuring the surface configuration and a method of producing magnetic recording medium using the same are also provided.

Abstract: A magnetic recording medium including a lubricating layer formed by using a lubricant containing first perfluoropolyether having one or more CH3 groups or one or more CF3 groups at two ends, and second perfluoropolyether having a polar group at least at one end.

Abstract: To provide a storage system capable of cutting back the resource while obtaining a WORM function. In the storage system, a controller (110) functions to: obtain, when a write request is made by a computer (300), information on one of logical devices that is a target of a write process, from a memory module (140); and inform, when the logical device is set to unwritable, a signal indicating that the logical device is set to unwritable, to the computer (300). An interface (200) functions to: reference meta-information held in a disk drive (130) to obtain a list of files that are not accessed for a predetermined period; secure a logical device that is capable of storing the files on the obtained list of files; and cause the controller (110) to store, in the logical device, the files on the list of files and set the logical device that stores the files in a manner that makes information stored in the memory module (140) unwritable.

Abstract: A storage device is provided with a file I/O interface control device and a plurality of disk pools. The file I/O interface control device sets one of a plurality of storage hierarchies defining storage classes, respectively, for each of LUs within the disk pools, thereby forming a file system in each of the LUs. The file I/O interface control device migrates at least one of the files from one of the LUs to another one of the LUs of an optimal storage class, based on static properties and dynamic properties of each file.

Abstract: While a large amount of files can be intensively managed, the capacity scalability is limited by the number of magnetic disk drives and the number of magnetic tape drives which can be connected to a system, thereby failing to provide satisfactory long-term management for a large amount of information which increases more and more over time. A storage system of the present invention is designed for connection with a heterogeneous storage which can be controlled by the storage system, and creates file systems in a storage area reserved within the storage system and in a storage area provided by the heterogeneous storage.

Abstract: While a large amount of files can be intensively managed, the capacity scalability is limited by the number of magnetic disk drives and the number of magnetic tape drives which can be connected to a system, thereby failing to provide satisfactory long-term management for a large amount of information which increases more and more over time. A storage system of the present invention is designed for connection with a heterogeneous storage which can be controlled by the storage system, and creates file systems in a storage area reserved within the storage system and in a storage area provided by the heterogeneous storage.

Abstract: The object of the present invention is to improve an access efficiency in a distributed environment. When a user “foo” access a file “file_1a” stored in a storage node SN1 under the control of a control node CN1 from a client CLN3 via a control node CN3 as shown by the solid lien arrow in the figure, a record of the access is accumulated in an access history of the control node CN1. If the control node CN1 refers to the access history and detects the frequent accesses from the control node CN3, it replicates or migrates the file “file_1a” to a storage node SN3 controlled by the control node CN3 as shown by the bold line arrow. The replication is performed if another device has accessed the file. Otherwise the migration is performed.

Abstract: A storage device is provided with a file I/O interface control device and a plurality of disk pools. The file I/O interface control device sets one of a plurality of storage hierarchies defining storage classes, respectively, for each of LUs within the disk pools, thereby forming a file system in each of the LUs. The file I/O interface control device migrates at least one of the files from one of the LUs to another one of the LUs of an optimal storage class, based on static properties and dynamic properties of each file.

Abstract: A computer system includes a first computer for receiving access requests to files from clients, a first storage device that is connected to the first computer and stores file management information, a second computer that receives access requests to data from the first computer, and a second storage device that is connected to the second computer and stores file data. Each time file data is received from the client, the first computer assigns identification information to the file data and stores the filename designated by the client and the identification information in the first storage device. The first computer stores the file data in the second storage device via the second computer.

Abstract: This invention addresses to execute an emergency access interception in a widely distributed environment. An access controller 100 manages an access control list (ACL) 110 recording access right to each object, and a black list (BL) 120 recording user information corresponding to the emergency access interception. The access controller 100 receives a request for authentication to access right and judges whether or not the access right is proper, first according to the BL 120 then ACL110. In case where the user information corresponding to the request is recorded in the BL 120, the access controller 100 sends out the user information to other access controllers and instructs them to register it in the black list. This invention effectively actualizes the emergency access interception under the widely distributed environment in case where the interception is required for any user.

Abstract: The object of the present invention is to maintain redundancy of file without using a centralized controller in a system where a plurality of file servers are connected with each other via a network. Each domain ND within a file storage system 10 includes a file server FS, a monitoring server WS, and a client CL, which are connected with each other via a LAN. When the file server FS detects a failure having occurred in another file server FS included in the system, it considers that redundancy of a file stored in the failed file server FS has decreased, and then determines whether or not it is responsible for recovering the redundancy. If the file server FS has determined that it is responsible for recovering the redundancy, it selects a file server FS as a file copy source and a file server FS as a file copy destination, and then copies based on the selection the identical file from the copy source server to the copy destination server.

Abstract: A magnetic disk to which is applied a first lubricating agent formed as (where p=0 or an integer of at least 1, q=0 or an integer of at least 1, and X=1-5), and over which is applied a second lubricating agent formed as HOCH2CF2(OC2F4)p(OCF2)qOCF2CH2OH (where p=0 or an integer of at least 1, q=0 or an integer of at least 1.

Abstract: Interfaces of SAN and NAS, prevents data miss even when a trouble occurs and makes it possible that an arbitrary number of NAS interfaces access the same file system with high performance. A storage system includes multiple interfaces for external connection, multiple disks accessed from multiple interfaces, and a shared memory accessed from multiple interfaces. The multiple interfaces are block interfaces executing disk block I/O request, and file interfaces of file servers executing file I/O request. A file system in the file servers is constructed in a part of the disks, and a log storage area holding change log of the file system, and a management file server information storage area holding information of managing file server performing exclusive access control of file system and management of log storage area are formed in the shared memory.

Abstract: A texture processing for imparting a magnetic orientation in the circumferential direction is applied to a substrate so as to impart a magnetic anisotropy to the magnetic disk in the circumferential direction. An underlying film, a magnetic recording film, a protective film, and a lubricating film are laminated one upon the other on the surface of the substrate. The surface of the magnetic disk has a value of the contact ratio [BH 1.0 nm] falling within a range of 7% to 15% in a region having a height not smaller than 1.0 nm, based on the height at which the contact ratio in the bearing curve of a surface roughness is 50%.

Abstract: A storage has NAS and SAN functions and a high degree of freedom to configure a system to reduce the management and operation cost. The storage includes a plurality of interface slots in which a plurality of interface controllers can be installed, a block I/O interface controller which has SAN functions and which can be installed in the slot, a file I/O interface controller which has NAS functions and which can be installed in the slots, a storage capacity pool including a plurality of disk devices accessible from the interface controllers, and a storage capacity pool controller to control the storage capacity pool.

Abstract: In a storage system with a server apparatus having at least one CPU, a memory, at least one network interface, and at least one storage interface, and, at least one disk connected to the storage interface, the server apparatus has a snapshot management part which maintains and manages snapshot of the disk apparatus, the disk apparatus has an operational volume which performs ordinary read/write and a differential volume which stores differential data of snapshot of the operational volume, the snapshot management part stores data on the operational volume in the differential volume, provides a preceding copy area to store its location information, and when free area on the differential volume becomes insufficient discards the stored location information and uses the preceding copy area as an free area.

Abstract: The invention provides both interfaces of SAN and NAS, prevents data miss even when a trouble occurs and makes it possible that an arbitrary number of NAS interfaces access the same file system with high performance. A storage system includes multiple interfaces for external connection, multiple disks accessed from multiple interfaces, and a shared memory accessed from multiple interfaces. The multiple interfaces are block interfaces executing disk block I/O request, and file interfaces of file servers executing file I/O request. A file system in the file servers is constructed in a part of the disks, and a log storage area holding change log of the file system, and a management file server information storage area holding information of managing file server performing exclusive access control of file system and management of log storage area are formed in the shared memory.

Abstract: A recording element or a reproducing element in a head generates heat that decomposes lubricating agent adhered to a slider surface near the recording/reproducing element of the head. This decomposed lubricating agent leads to corrosion of the magnetic layer and the like of the magnetic disk. The lubricating agent undergoes volume expansion due to this corrosion, creating a protrusion on the magnetic disk surface to which the lubricating agent is adhered. The magnetic disk surface to which the lubricating agent is adhered comes into contact with the magnetic head, leading to friction with the protective layer, the magnetic layer, and the like. In the worst case, this can lead to secondary errors where data recorded on the magnetic layer is erased.