Abstract:
Even if abnormality occurs in part of a plurality of data processing resources, data processing is executed by using a normal resource(s). Each of a plurality of storage apparatuses includes a host communication control unit, a controller, and a storage device communication control unit. If abnormality occurs in the host communication control unit of a local system or the storage device communication control unit of the local system, the controller of each system selects a normal resource, as a resource to be used for processing after the occurrence of the abnormality, from the host communication control unit of the local system or the storage device communication control unit of the local system, executes processing of a command for the local system, which is issued from a host computer after the occurrence of the abnormality, by using the selected resource, and requests the storage apparatus of the other system via a data transfer path to execute part of the processing of the command for the local system.
Abstract:
In various embodiments, the present invention provides virtual disk formatting by intermediate devices including: (1) a storage shelf router and the storage shelf in which the storage-shelf is included, to external computing entities, such as disk-array controllers and host computers; (2) an I/O controller; and (3) a storage-bridge device. Additional embodiments of the present invention enhance virtual formatting by using additional padding, in a dual-abstraction method, to efficiently align virtual-block reads with underlying device blocks. Yet additional embodiments of the present invention allow for tracking and correcting device blocks corrupted during READ-MODIFY operations that occur during virtual-block WRITE operations. Various intermediate devices may employ two or more of the virtual formatting, dual abstraction, and corrupted-device-block tracking methods.
Abstract:
A media area network (10) includes a storage system (16) having at least one storage device (18) for storing digitized information. A host bus (14) adapter provides a link between the storage system and a host system (12) that provides overall control of the media area network. Within the host bus adapter, a lower-level port driver (24) monitors communications between the storage system and the host bus adapter. In the event of a communications failure, the lower-level port driver initiates switching from a failed port to an alternative port, thereby achieving fail-over recovery. Allocating the responsibility for fail-over recovery to the lower-level port driver assures timely handling of port failures, thereby reducing potential latency delays.
Abstract:
A storage server (100) in a storage area network (SAN) environment connecting host computers (106) and storage devices (104). The storage server (100) includes a plurality of storage processors and a switching circuit. Data is routed between the storage processors via the switching circuit according to routing tags. The routing tags are examined prior to completely receiving the data, allowing the data to be routed with minimal delay.
Abstract:
A method, system, and apparatus for accessing a plurality of storage devices in a storage area network (SAN) as network attached storage (NAS) in a data communication network is described. A SAN server includes a first interface and a second interface. The first interface is configured to be coupled to the SAN. The second interface is coupled to a first data communication network. A NAS server includes a third interface and fourth interface. The third interface is configured to be coupled to a second data communication network. The fourth interface is coupled to the first data communication network. The SAN server allocates a first portion of the plurality of storage devices in the SAN to be accessible through the second interface to at least one first host coupled to the first data communication network. The SAN server allocates a second portion of the plurality of storage devices in the SAN to the NAS server. The NAS server configures access to the second portion of the plurality of storage devices to at least one second host coupled to the second data communication network.
Abstract:
A data storage system having a plurality of disk drives. Each one has a pair of ports. A pair of directors controls the flow of data to and from the disk drives. A first and second fibre channel port by-pass selector section are provided. The first fibre channel selector section includes: an input/output port coupled to a first one of the directors; and, a plurality of output/input ports connected between a first one of the ports of the plurality of desk drives through a first plurality of fibre channel links. The first fibre channel port by-pass selector section is adapted to couple the first one of the directors serially to one, or ones, of the first ports of the plurality of disk drives through a first fibre channel selectively in accordance with a control signal fed to the first fibre channel by-pass selector section. The first fibre channel includes one, or more, of the first plurality of fibre channel links. The second fibre channel port by-pass selector section is similarly configured.
Abstract:
System, apparatus and method for interconnecting computer devices define an interconnect topology maximizing performance and device availability in the event of a communication channel failure. Structure and method are particularly relevant and beneficial to a computer RAID disk interconnection topology for Fibre Channel connections to improve RAID array performance and data availability, but is not limited to such RAID systems, and other devices may be interconnected according to the structure and method of the invention. A topology having multiple dual-ported controllers configured in a tube topology is provided for a switchable configuration having a plurality of channels and a plurality of controllers arranged in a tube topology or structure. In the event of a channel failure for this structure, the load will be evenly distributed to the remaining controllers. One embodiment provides a data storage system having a plurality of storage devices each having first and second access ports, a plurality of communication channels, a controller controlling access by the plurality storage devices to the plurality of channels, where at least one of the devices is connected via the first access port to a first one of the channels and via the second access port to a second one of the channels, so that the one device may be accessed by the controller via either the first or second channel. Mathematical relationships between the minimum number of devices for an automatically balanced system and the number of channels are described.
Abstract:
A method for reducing the time necessary to recover from a processor (111, 121) failure in a fault-tolerant computer system with redundant server computer systems (110, 120) with their own disk storage systems is disclosed and claimed. In normal operation whenever data is to be written to disk storage, each of the servers writes an identical copy of the data to its own disk storage system. When a server processor fails and then is restored to operation, that server's disk storage system must be made identical to (consistent with) the disk storage system of the non-failing server before the system is again fault tolerant. This method improves performance by electronically transferring the disk storage system from the failing server to a non-failing server, having the non-failing server keep the transferred disk storage system identical to its normal disk storage system, and reconnecting the transferred disk storage system to the failed server when it again becomes available. This minimizes the processing time required to make the disk storage contents identical, both at the time of failure and at the time of restoration.
Abstract:
The disk array control system is a fault tolerant controller for arrays of hard disk drives. With the controller (8) as a front end, an array of hard disk drives (12) would appear as a single drive to a host computer system (7) connected to the controller. The controller translates input/output data requests (300) from the host system (7) to input/output data transfer requests for the appropriate drives in the drive array (12). To minimize latency, translation techniques provide for a minimal number of accesses to the drives in the array. Queued input/output requests are supported, and, to maximize throughput, optimal scheduling techniques are used to optimize resource usage and minimize drive access overheads. Means are provided for detecting module failures, sustaining operation after failure, and replacing faulty modules without interrupting service.