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: In a distributed file system, when a user requests a computer to create a distributed file, a management computer acquires a list of computers complying with an allocation rule selected by the user from allocation rules taking the performance, security level, reliability level and utility rate into consideration. When the user requests the computer to access the distributed file, on the other hand, the partial files and the server information are collected from each computer. Each computer evaluates the allocation of the partial files based on the selected allocation rule and the server information from each computer, and if required, selects a destination computer and instructs the partial files to be moved to the destination computer.

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: Provided is a computer system containing plural storage systems which manages the bandwidth of the storage systems in accordance with storage area attributes. The computer system is characterized in that: a control unit incorporates related file information in metadata, the related file information containing information for identifying a second file which to be write-accessed in conjunction with access to a first file by a client computer, and an access type of the write access. The control unit refers to the related file information to obtain the second file and the access type when the first file is accessed by the client computer. The control unit reads, from the obtained second file stored in the disk device, data corresponding to the obtained access type, to store the read data in a cache memory.

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: According to one embodiment, there is provided a method of manufacturing a magnetic recording media including depositing a magnetic layer on a substrate and processing the magnetic layer to form protruded magnetic patterns, depositing a planarizing layer in recesses between the magnetic patterns and on the magnetic patterns, and forming steps on a surface of the planarizing layer.

Abstract: In a distributed file system, when a user requests a computer to create a distributed file, a management computer acquires a list of computers complying with an allocation rule selected by the user from allocation rules taking the performance, security level, reliability level and utility rate into consideration. When the user requests the computer to access the distributed file, on the other hand, the partial files and the server information are collected from each computer. Each computer evaluates the allocation of the partial files based on the selected allocation rule and the server information from each computer, and if required, selects a destination computer and instructs the partial files to be moved to the destination computer.

Abstract: A tape library comprises: a plurality of tape media; a plurality of slots in which the plurality of tape media are respectively stored; a drive in which a tape medium extracted from any of the plurality of slots is set and which performs tape reading or writing in respect of this tape medium; and a controller by which a tape medium is extracted from a designated slot of these plurality of slots and set in the drive. The host computer comprises: a plurality of virtual computers; a first storage region in which is stored slot allocation information expressing which slot is allocated to which virtual computer; and an access control unit that specifies the slot allocated to a first virtual computer, of the plurality of the virtual computers, from the slot allocation information, and restricts access from the first virtual computer to the tape medium in the specified slot.

Abstract: In order to manage the various types of attribute information within the storage system, the storage system includes the following databases within a file-access controlling memory: a database for managing index information for managing contents of the files, and an index retrieval program, a database for managing the attribute information on the files, and a database for managing storage positions of blocks configuring a file. When the storage system receives an access request to a file, the utilization of these databases allows the storage system to make the access to the access-target file.

Abstract: In order to manage the various types of attribute information within the storage system, the storage system includes the following databases within a file-access controlling memory: a database for managing index information for managing contents of the files, and an index retrieval program, a database for managing the attribute information on the files, and a database for managing storage positions of blocks configuring a file. When the storage system receives an access request to a file, the utilization of these databases allows the storage system to make the access to the access-target file.

Abstract: Snapshots are implemented by combining original data in a place where an operational volume has been updated with data in a place where the operational volume has not been updated. A snapshot management table maintains a value indicating that update has not been conducted, or a storage place of original data, for each of combinations of blocks in the operational volume and the snapshots. If there is a snapshot in which update has not been conducted in a update place at the time of update, then original data is copied and the snapshot management table is updated. The copied original data is managed by a difference block management table, which has a value indicating whether respective snapshots are referencing the data. If a snapshot is deleted, then the value indicating that the snapshot is referencing is altered in all entries in the difference block management table.

Abstract: A network storage system accessible by a computer, including worm functions.

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: 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: Snapshots are implemented by combining original data in a place where an operational volume has been updated with data in a place where the operational volume has not been updated. A snapshot management table maintains a value indicating that update has not been conducted, or a storage place of original data, for each of combinations of blocks in the operational volume and the snapshots. If there is a snapshot in which update has not been conducted in a update place at the time of update, then original data is copied and the snapshot management table is updated. The copied original data is managed by a difference block management table, which has a value indicating whether respective snapshots are referencing the data. If a snapshot is deleted, then the value indicating that the snapshot is referencing is altered in all entries in the difference block management table.

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: A storage system capable of cutting back the resource while obtaining a WORM function. 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; and cause the controller (110) to store, 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 computer system for managing log information, enabling correct comprehension of system logs for an identical resource before and after migration among plural nodes. A global ID, being unique in the system, is given to a resource (LU) migrated from one file share server to another. The global ID remains the same in the migration destination file share server after migration and log messages for the resource are obtained based on the global ID.

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: Provided is a storage system capable of preventing the access performance from a client to a file system from deteriorating even when a file system is migrated among a plurality of file servers. This storage system provided a shared file system having the same namespace to the client accessing the file system. This storage system stores in its memory a first information table storing the correspondence of the file system and the file server mounting the file system, and a second information table storing the correspondence of the file system and the frequency of access by the client to the file system.