摘要:
A method and apparatus for transferring data between two storage media, and is used in an illustrative embodiment to transfer data between two storage media in a shadow set, the storage media being accessible to one or more host processors. The method of the preferred embodiment includes the steps of: A. receiving a command from one of the host processors, the command specifying data to be transferred from a first storage medium to a second storage medium; B. transferring the data specified in the command received from the host from the first storage medium to the second storage medium in a series of subtransfers, each of the subtransfers transferring a portion of the data; and C. processing one or more I/O requests to the shadow set received from one or more host processors by, for each received I/O request: a. implementing the I/O request if the I/O request does not involve a section of the shadow set currently involved in one of the subtransfers; and b. stalling the I/O request if the I/O request involves a section of said shadow set currently involved in one of the subtransfers, and implementing the I/O request when the subtransfer has completed.
摘要:
A digital data management system for managing a shadow set of storage media includes a plurality of storage media each accessible by at least one data processing device for I/O operations. Successive comparisons are carried out between data stored in corresponding locations in the storage media while maintaining access to the storage media for I/O operations. When inconsistency between data in corresponding locations is detected, a management operation is performed on at least one of the shadow set storage media. The management operation includes interrupting I/O operations to at least the storage medium on which the operation is performed, modifying data on one of the shadow set storage media to correct the inconsistency, and resuming availability of the storage media for I/O operations.
摘要:
A log for managing data in a shadow set of storage media includes a system for maintaining a log of address information associated with at least one write command received from one of a plurality of data processing devices. The system for maintaining a log of address information includes a device for receiving a write command from a data processing device, a device which writes data associated with the write command in a section of one of the storage media, and a device which writes address information in a log indicative of the location of that section. A device is provided which then implements a management operation on data stored on one of the storage media in accordance with the address information stored in the log.
摘要:
A system and method for transferring data from a first storage medium to a second storage medium, each of the storage media being divided into corresponding data blocks, the method comprising steps of: (a) reading data stored in a first data block in the first storage medium, the first data block initially constituting a current data block; (b) comparing data read in the current data block to data stored in a corresponding data block in the second storage medium; (c) if the data compared in step b are identical, reading data stored in a different data block in the first storage medium, the different data block becoming the current data block, and returning to step b; (d) modifying the data stored in one of the storage media such that the data in the current data block is identical to the corresponding data in the second storage medium; and (e) rereading the data in the current data block and returning to step b.
摘要:
A network of computer node interface to globally addressable memory system that provides persistent storage of data exchange periodic connectivity information. The exchanged connectivity information provides information regarding node failure to other nodes in the system, and the surviving nodes use the information to determine which node, if any, has ceased functioning. Various processes are used to recover the portion of the global address space for which the failed node was responsible, including RAM directory, disk directory, or file system information. Additionally, nodes may be subdivided into groups and connectivity information is exchanged between nodes belonging to a group. Each group then exchanges group-wise connectivity information and failures may be recovered.
摘要:
A multi-user file storage service and system enable each user of a pre-subscribed user group to communicate with a remote file server node via a wide area network and to access the files of the file group via the respective client node. More than one user of the pre-subscribed user group is permitted to access the file group at the remote file server node simultaneously. Integrity of the files at the remote file server node are maintained by controlling each access to each file at the remote file server node so that each access to files at the remote file server is performed, if at all, on a respective portion of each file as most recently updated at the remote file server node. Additionally, an encrypted key is transferred from the file server node to a particular client node via a secure channel. The encrypted key uses an encryption function and a decryption function not known locally at the remote file server. Furthermore, both privileged access control rights and file sharing mode access control to a particular file of the group of files are delegated to one or more distributed nodes other than the remote file server node which provides the data.
摘要:
In a network of computer nodes, a directory service provides both the physical location of directory information around the network and the directory information itself in a single data structure. This single data structure is distributed throughout the network, and continuously redistributed, so as to create a directory service that is both more flexible, and more robust, than prior art directory services.
摘要:
A management capability is provided for a virtual computing platform. In one example, this platform allows interconnected physical resources such as processors, memory, network interfaces and storage interfaces to be abstracted and mapped to virtual resources (e.g., virtual mainframes, virtual partitions). Virtual resources contained in a virtual partition can be assembled into virtual servers that execute a guest operating system (e.g., Linux). In one example, the abstraction is unique in that any resource is available to any virtual server regardless of the physical boundaries that separate the resources. For example, any number of physical processors or any amount of physical memory can be used by a virtual server even if these resources span different nodes.
摘要:
In a network of computer nodes, a directory service provides both the physical location of directory information around the network and the directory information itself in a single data structure. This single data structure is distributed throughout the network, and continuously redistributed, so as to create a directory service that is both more flexible, and more robust, than prior art directory services.
摘要:
A multi-user file storage service and system enables each user of a user group to operate an arbitrary client node at an arbitrary geographic location to communicate with a remote file server node via a wide area network. More than one user of the user group is permitted to access the file group at the remote file server node simultaneously, but the integrity of the files is maintained by controlling access so that each access to one of the files at the remote file server is performed, if at all, on a respective portion of that file as most recently updated at the remote file server node.