Abstract: By incorporating a referral mechanism, a failover method and system for remotely mirrored clustered file servers enables a client computer to transparently access a remotely mirrored file system during a failover of a first NAS (network attached storage) storing the file system. The first NAS is clustered with a second NAS that takes over the IP address of the first NAS on failover. A mirroring relationship is established between the first NAS and a third NAS whereby a copy of the file system is replicated to the third NAS. A referral is created on the second NAS, such that an access attempt from the client computer for accessing the first file system that is directed to the second NAS following IP address takeover from the first NAS after failover is referred to the third NAS by the referral to enable the client computer to access the copy of the file system.

Abstract: One code (a compressed redundant code) is created based on a plurality of first redundant codes, each created on the basis of a plurality of data units, and this compressed redundant code is written to a nonvolatile storage area. This compressed redundant code is used to restore either a data element constituting a multiple-failure data, or a first redundant code corresponding to the multiple-failure data, which is stored in an unreadable sub-storage area of a partially failed storage device, and to restore the data element constituting the multiple-failure data which is stored in a sub-storage area of a completely failed storage device, based on the restored either data element or first redundant code, and either another data element constituting the multiple-failure data or the first redundant code corresponding to the multiple-failure data.

Abstract: A stator includes a stator core and a distributed winding type multi-phase coil. This coil includes unit coils made by winding a flat conductor wire in plural turns. The unit coils are mounted in slots of the stator core and connected with each other. Each unit coil includes an outer-layer coil and an inner-layer coil each being concentrically wound. Those two layer coils are made of a single continuous flat conductor wire. A winding start portion of the outer-layer coil and a winding end portion of the inner-layer coil form first and second connection end portions of the unit coil respectively. The first and second connection end portions are located separately on both edges of the unit coil above an upper end face of the stator core. The first connection end portion is placed close to an inner circumference of the stator core and the second connection end portion is placed close to an outer circumference of the stator core.

Abstract: The storage system provides a logical volume and includes a plurality of disk devices and a controller, coupled to the plurality of disk devices, which manages a plurality of storage areas provided by the plurality of disk devices. The host includes an application which sends data to a logical volume and an operating system which manages a block position of the logical volume. If the operating system receives a request from the application to expand a first capacity of the logical volume, the operating system sends a write request to the logical volume. In response to the write request, the controller allocates at least one of the plurality of storage areas to the logical volume. The controller monitors a second capacity of storage areas allocated to the logical volume relative to a third capacity of the plurality of storage areas.

Abstract: A storage apparatus, which controls the input and output of data to and from a computer, includes a logical volume for storing data from the computer, a common resource for storing data pre-stored in the logical volume as update data in order to store subsequent data from the computer in the logical volume, an encryption/decryption unit for encrypting or decrypting data stored in the logical volume or update data stored in the common resource, and a key change unit for changing a key for encrypting or decrypting data stored in the logical volume. The storage apparatus changes the key for encrypting or decrypting update data stored in the common resource based on information of the key used for data stored in the logical volume.

Abstract: Proposed is an apparatus and method of preventing the leakage of information from an external storage apparatus even when such external storage apparatus is stolen or accessed from an unauthorized host computer. This external storage apparatus accessible from a host computer or another external storage apparatus via a network encrypts or decrypts data written from a host computer to be stored in the storage area, sends a request for existence confirmation to the host computer or the other external storage apparatus every predetermined period of time, and zeroizes an encryption key to be used in the encryption calculation for encrypting or decrypting data to be performed by the encryption calculation unit based on the result of a response from the host computer or the other external storage apparatus in reply to the request.

Abstract: Data of a global file system spread over multiple local NAS systems may be consolidated as a copy into a single remote NAS system. When remote copy is set up, the local NAS systems replace referrals within the global file system with directories and send these in place of the referrals to the remote NAS system. Then, other local NAS systems referred to by the referrals send files and directories under the directories replacing the referrals on the remote NAS system. Alternatively, to split copy data of a locally-stored global file system amongst multiple remote NAS systems, the local NAS system replaces specified directories with referrals, and sends the referrals with the data to one of the remote NAS systems. Then, the local NAS system sends files and directories under the directories replaced with referrals to one or more other remote NAS systems as referred to by the referrals.

Abstract: One code (a compressed redundant code) is created based on a plurality of first redundant codes, each created on the basis of a plurality of data units, and this compressed redundant code is written to a nonvolatile storage area. This compressed redundant code is used to restore either a data element constituting a multiple-failure data, or a first redundant code corresponding to the multiple-failure data, which is stored in an unreadable sub-storage area of a partially failed storage device, and to restore the data element constituting the multiple-failure data which is stored in a sub-storage area of a completely failed storage device, based on the restored either data element or first redundant code, and either another data element constituting the multiple-failure data or the first redundant code corresponding to the multiple-failure data.

Abstract: A volume provider unit in a computer system that detects a logical block address of a read or write I/O accessing a logical volume of a storage device from a host. According to the logical block address fetched, a storage domain of the logical volume is dynamically expanded. Moreover, the storage domain of the logical volume is reduced or expanded according to an instruction of logical volume capacity reduction or expansion from a host commander part to a volume server.

Abstract: A volume provider unit in a computer system that detects a logical block address of a read or write I/O accessing a logical volume of a storage device from a host. According to the logical block address fetched, a storage domain of the logical volume is dynamically expanded. Moreover, the storage domain of the logical volume is reduced or expanded according to an instruction of logical volume capacity reduction or expansion from a host commander part to a volume server.

Abstract: Techniques to assure genuineness of data stored on a storage device are provided. The storage device includes a storage controller that conducts I/O operations and management operations. A description of management operations and corresponding timestamps are recorded to an operation log stored in a memory. The memory additionally stores an attribute for each storage volume of the storage device. Write access to each of the storage volumes is dependent on the attribute.

Abstract: Data of a global file system spread over multiple local NAS systems may be consolidated as a copy into a single remote NAS system. When remote copy is set up, the local NAS systems replace referrals within the global file system with directories and send these in place of the referrals to the remote NAS system. Then, other local NAS systems referred to by the referrals send files and directories under the directories replacing the referrals on the remote NAS system. Alternatively, to split copy data of a locally-stored global file system amongst multiple remote NAS systems, the local NAS system replaces specified directories with referrals, and sends the referrals with the data to one of the remote NAS systems. Then, the local NAS system sends files and directories under the directories replaced with referrals to one or more other remote NAS systems as referred to by the referrals.

Abstract: A storage system comprises a plurality of processors, a plurality of volumes, and interconnecting means to connect the plurality of processors and the plurality of volume to each other. The storage system detects and determines the cause of the performance bottleneck, wherein the cause may be one of plurality of reasons. The storage system applies an appropriate load balancing method according to the determined cause of the performance bottleneck.

Abstract: Data of a global file system spread over multiple local NAS systems may be consolidated as a copy into a single remote NAS system. When remote copy is set up, the local NAS systems replace referrals within the global file system with directories and send these in place of the referrals to the remote NAS system. Then, other local NAS systems referred to by the referrals send files and directories under the directories replacing the referrals on the remote NAS system. Alternatively, to split copy data of a locally-stored global file system amongst multiple remote NAS systems, the local NAS system replaces specified directories with referrals, and sends the referrals with the data to one of the remote NAS systems. Then, the local NAS system sends files and directories under the directories replaced with referrals to one or more other remote NAS systems as referred to by the referrals.

Abstract: A volume provider unit in a computer system that detects a logical block address of a read or write I/O accessing a logical volume of a storage device from a host. According to the logical block address fetched, a storage domain of the logical volume is dynamically expanded. Moreover, the storage domain of the logical volume is reduced or expanded according to an instruction of logical volume capacity reduction or expansion from a host commander part to a volume server.

Abstract: In a storage system, a server apparatus and a storage apparatus are provided, while the server apparatus is connected via a LAN to one, or plural sets of computers so as to accept an access request of file data issued from the computers, whereas the storage apparatus is connected via a wide area network to the server apparatus so as to store thereinto the file data. A communication between the computers and the server apparatus is carried out by employing a network file protocol, whereas a communication between the server apparatus and the storage apparatus is performed by employing a block device protocol. The server apparatus and the storage apparatus are connected via the respective security protecting apparatus to the wide area network.

Abstract: Computerized information system and method having multiple virtual machines share common resources such as the system storage resources. The system contains a host computer executing multiple virtual machines, system resources organized into multiple resource groups, and a resource controller associating a resource group with a virtual machine executing on the host computer. When a state of the virtual machine changes, the resource controller releases the previously allocated resource group and when a request to execute another virtual machine is received, a new resource group is allocated to the host computer.

Abstract: A system and method for object-level snapshot creation in an object-based storage system. The host device includes a first object management table (OMT) and a file system. The object-based storage system is connected to the host device and includes a controller and object-based storage devices (OSD). The controller includes a snapshot module, a second OMT. The snapshot module receives and processes OSD and other commands from the file system or a service processor, creates an original object and a mirror object in an OSD, and initiates a snapshot operation in an OSD. The first OMT may also reside at a metadata server. A snapshot operation may be a mirror operation or a copy on write operation. The first OMT and the second OMT maintain mapping information of a file identifier, a partition ID, and an object ID, and an object status and a generation number of snapshots.

Abstract: Proposed is an apparatus and method of preventing the leakage of information from an external storage apparatus even when such external storage apparatus is stolen or accessed from an unauthorized host computer. This external storage apparatus accessible from a host computer or another external storage apparatus via a network encrypts or decrypts data written from a host computer to be stored in the storage area, sends a request for existence confirmation to the host computer or the other external storage apparatus every predetermined period of time, and zeroizes an encryption key to be used in the encryption calculation for encrypting or decrypting data to be performed by the encryption calculation unit based on the result of a response from the host computer or the other external storage apparatus in reply to the request.

Abstract: A storage system capable of managing information in accordance with system configuration changes is provided. When sub-storage systems 20A, 20B are connected to each other, a storage system 100 is managed in such a manner that the sub-storage systems 20A and 20B are connected to each other via a connection cable 44 to constitute modules 20A and 20B respectively, pieces of coupling control information of the respective modules 20A, 20B are coupled together, and the modules 20A, 20B are recognized as a single access target for data input/output requests from a host 51A.