摘要:
A file system is migrated from a source file server to a target file server in a data network while permitting clients to have concurrent read/write access to the file system. The target file server issues directory read requests and file read requests to the source file server in accordance with a network file access protocol to transfer the file system from the source file server to the target file server. Concurrent with the transfer of the file system from the source file server to the target file server, the target file server responds to client read/write requests for access to the file system. In a preferred embodiment, the target file server maintains a hierarchy of on-line nodes off-line nodes. The online nodes represent file system objects that have been completely migrated, and the offline nodes representing file system objects that have not been completely migrated. The target file server executes a background process that walks through the hierarchy in order to migrate the objects of the offline nodes. When an object has been completely migrated, the target file server changes the offline node for the object to an online node for the object.
摘要:
Consistent updates are made automatically over a wide-area IP network, concurrently with read-only access to the remote copies. A replication control protocol (RCP) is layered over TCP/IP providing the capability for a remote site to replicate and rebroadcast blocks of the remote copy data to specified groups of destinations, as configured in a routing table. A volume multicast layer over RCP provides for multicasting to specified volume extents of the blocks. The blocks are copied at the logical level, so that it does not matter what physical structure is used for storing the remote copies. Save volumes buffer the remote copy data transmitted between the primary or secondary file system volume and the IP network, in order to ensure independence between the replication process, the IP transport method, and the primary file system being replicated.
摘要:
A data storage system receives sets of the revisions such that each set of revisions changes the dataset from one consistent state to another. Each set of revisions is processed in a write-selected phase followed by a read-selected phase. In the write-selected phase, the revisions in each set are written to a buffer and processed to produce a directory of the set of revisions. In the read-selected phase, the revisions are read from the buffer and integrated into the dataset. When one set of revisions is in the read-selected phase, the next set of revisions is in the write-selected phase. To permit uninterrupted read-only access to a consistent state of the dataset, the data storage system responds to a request for reading specified data on a priority basis by first accessing the directory of the read-selected revisions to determine whether the specified data are in the read-selected set of revisions, and if so, the specified data are read from the read-selected set of revisions, and if not, the specified data are read from the dataset. In a preferred implementation, the sets of revisions are alternately written to either a first buffer or a second buffer, and processing of each set of revisions is switched from the write-selected phase to the read-selected phase by switching between the two buffers.
摘要:
Software is supplied via data storage system. A software image is provided to the data storage system from an external website. It is determined that software needs to be installed on a host. The software image is retrieved from the data storage system. The software is installed on the host using the software image.
摘要:
Described are techniques for use in controlling information about a data storage system returned to an end user. A first set of information is sent from a first recipient location included in a hierarchy to a second recipient location included in the hierarchy. At the second recipient location, a second set of information is produced using information control criteria of said second recipient location. The second set of information is sent from the second recipient location to a component used to manage the data storage system.
摘要:
A method is used in managing metadata. Data of an object is stored in a magnetic hard disk set in an object addressable data storage system. Metadata for the object is stored in an SSD set in the object addressable data storage system. The metadata includes information necessary for determining the location of the data of the object in the magnetic hard disk set.
摘要:
An improved policy enforcement architecture includes several components that improve the performance of policy enforcement in a hierarchical storage environment. A File System Query instruction permits a richer set of queries to be expressed by a policy engine, thereby permitting more complex policies to be implemented with ease. The File System result is generated at the file server, and only files of interest are forwarded to the policy engine. The file system query advantageously may be applied against a pre-generated index having one more characterizing attributes to further reduce the processing required to retrieve policy data. An Index Build instruction, added to a programming interface, allows a policy engine generate the characterizing indices in advance of use. Index maintenance techniques maintain consistency between the index and the file system to ensure that the policy can be enforced using accurate file information.
摘要:
Methods, systems, and computer program products for providing access to shared storage by a plurality of nodes are disclosed. According to one method, at a node of a plurality of nodes sharing access to a disk array, an application input/output (I/O) operation and whether sufficient space in the disk array has been mapped at the node for the I/O operation are detected. In response to detecting that sufficient space in the disk array has not been mapped at the node for the I/O operation, a map for the I/O operation including physical disk access information is requested and obtained from a server. The physical disk access information included within the map for the application I/O operation obtained from the server is used to perform the I/O operation by accessing the disk array without intervention by the server.
摘要:
File system cells are linked together to form a meta file system that appears to a user or application program to be a single file system. The meta file system permits concurrent access by multiple processors in a file server wherein each file system cell is managed by a respective one of the processors. The file server responds to a directory access request by returning a file handle containing a file system cell ID and a pointer to a file in the file system cell. The file server responds to a subsequent file access request including the file handle by extracting the file system cell ID and the pointer to the file, searching a routing table for an entry having a file system cell ID matching the file system cell ID extracted from the file handle, and routing the request to the processor managing the file system cell.
摘要:
A method is used in applying XAM processes. A set of content is received via any of a file system interface, a block based interface, an object based interface to an object addressable data storage system. An object derived from the set of content and having an object identifier is stored in the object addressable data storage system. The object is made available for retrieval via the object based interface using the object identifier.