Abstract: An architecture, including a file-level protocol, for supporting sparse volumes on a storage system is provided. The file-level protocol provides coherency checking for use in retrieving data stored on a backing store remote from a storage system.

Abstract: A network caching system has a multi-protocol caching filer coupled to an origin server to provide storage virtualization of data served by the filer in response to data access requests issued by multi-protocol clients over a computer network. The multi-protocol caching filer includes a file system configured to manage a sparse volume that “virtualizes” a storage space of the data to thereby provide a cache function that enables access to data by the multi-protocol clients. To that end, the caching filer further includes a multi-protocol engine configured to translate the multi-protocol client data access requests into generic file system primitive operations executable by both the caching filer and the origin server.

Abstract: In one embodiment, the invention provides a method of transforming a request from a client to a proxy cache, the method comprising: receiving a request from a client, where the request is based upon a first open standard protocol; and translating the request from the first open standard protocol into a second open standard protocol at a file system level; and transmitting the request in the second open standard protocol to a server.

Abstract: In one embodiment, the invention provides an apparatus for caching data in a network, with the apparatus including a proxy cache configured to receive request for an object from a client and to fetch data blocks from a server. The proxy cache may be configured to cache the data blocks in a hierarchical relationship within the object. The object may be, for example, a data file or a directory. The data blocks that are cached in the proxy cache define an active data set which is based upon a request from a client.

Abstract: A method of operating a storage system includes moving a block of data stored in the storage system to a new location in the storage system, such as for purposes of defragmentation. After the block has been moved to the new location, the storage system receives a request requiring access to the block. The storage system uses metadata appended to an identified block to detect that the block may have been relocated. The metadata can further be used to distinguish a block that has been relocated from a lost write.

Abstract: A technique converts a stream of virtual volume block numbers (vvbns) into a hybrid virtual volume (vvol) file system containing both physical volume block numbers (pvbns) and vvbns. The stream of vvbns is illustratively embodied as a file system data stream of a vvol that is transferred by a source to a destination in accordance with image transfer operations, such as volume copying and synchronous or asynchronous mirroring. Transfer of the vvol involves converting a file system on the source vvol into the file system data stream (i.e., a “pure” vvol stream), where all blocks of the vvol are represented by vvbns. The file system data stream is then transferred to the destination, where the vvbns of the pure vvol stream blocks are converted to pvbns of a hybrid stream.

Abstract: A technique translates a hybrid virtual volume (vvol) having a file system that contains intermingled virtual and physical volume block numbers (vbns) into a “pure” stream of virtual vbns (vvbns). The stream of vvbns is illustratively embodied as an output file system data stream of a vvol image that is transferred by a source storage system (“source”) to a destination storage system (“destination”) in accordance with image transfer operations, such as volume copying and synchronous or asynchronous mirroring, provided by a volume replication facility. The blocks that are sent as part of the image transfer are selected from a container file of the hybrid vvol on the source. In particular, the invention is directed to a technique for translating physical vbns (pvbns) of a source aggregate on the source to pure vvbns of the output file system data stream that can be used on a destination aggregate of the destination, where embedded pvbns in the source hybrid vvol image are not valid.

Abstract: In one embodiment, a method of processing data in a network with multiple proxy caches, includes: pushing cached data in a first proxy cache to at least one other proxy cache in a cluster configuration; caching the data from the first proxy cache; and permitting a client to access the data in the at least one other proxy cache in the cluster configuration. In another embodiment, a method of processing data in a network with multiple proxy caches, includes: providing a snapshot replica from a first server to second server; and permitting a proxy cache to access the second server for data in the snapshot replica, in response to a disconnect operation of the first server.

Abstract: In one embodiment, the invention provides an apparatus for caching data in a network, with the apparatus including a proxy cache configured to receive request for an object from a client and to fetch data blocks from a server. The proxy cache may be configured to cache the data blocks in a hierarchical relationship within the object. The object may be, for example, a data file or a directory. The data blocks that are cached in the proxy cache define an active data set which is based upon a request from a client.

Abstract: In one embodiment, the invention provides an apparatus for caching data in a network, with the apparatus including a proxy cache configured to receive request for an object from a client and to fetch data blocks from a server. The proxy cache may be configured to cache the data blocks in a hierarchical relationship within the object. The object may be, for example, a data file or a directory. The data blocks that are cached in the proxy cache define an active data set which is based upon a request from a client.

Abstract: In one embodiment, the invention provides a method of transforming a request from a client to a proxy cache, the method comprising: receiving a request from a client, where the request is based upon a first open standard protocol; and translating the request from the first open standard protocol into a second open standard protocol at a file system level; and transmitting the request in the second open standard protocol to a server.