Abstract: Caching techniques for use in a computer system comprising a core and at least one edge device. The core comprises at least one object addressable storage system. At least one cache is disposed logically between the core and the edge device. The cache has a prefetch policy that selects from among the content units based upon at least one prefetch criterion. Prefetching can be enabled or disabled in response to at least one criterion based upon information associated with an individual access request.

Abstract: One embodiment is directed to the deletion of content units from a storage system. When a content unit is deleted, a reflection may be created and stored on the storage system. The reflection identifies the deleted content unit and may include additional information, such as a portion of the content of the content unit and audit information regarding the deletion of the content unit.

Abstract: One embodiment is a system for locating content on a storage system, in which the storage system provides a location hint to the host of where the data is physically stored, which the host can resubmit with future access requests. In another embodiment, an index that maps content addresses to physical storage locations is cached on the storage system. In yet another embodiment, intrinsic locations are used to select a storage location for newly written data based on an address of the data. In a further embodiment, units of data that are stored at approximately the same time having location index entries that are proximate in the index.

Abstract: One embodiment is a system for locating content on a storage system, in which the storage system provides a location hint to the host of where the data is physically stored, which the host can resubmit with future access requests. In another embodiment, an index that maps content addresses to physical storage locations is cached on the storage system. In yet another embodiment, intrinsic locations are used to select a storage location for newly written data based on an address of the data. In a further embodiment, units of data that are stored at approximately the same time having location index entries that are proximate in the index.

Abstract: One embodiment is directed to the deletion of content units from a storage system. When a content unit is deleted, a reflection may be created and stored on the storage system. The reflection identifies the deleted content unit and may include additional information, such as a portion of the content of the content unit and audit information regarding the deletion of the content unit.

Abstract: Access to content addressable data on a network is facilitated using digital information storing devices or data repositories (“silos”) that monitor broadcast data requests over the network. A number of silos automatically monitor both data requests and data itself that are broadcast over a network. The silos selectively store data. Each silo responds to data requests broadcast over the network with data the silo has previously intercepted. A content addressable file scheme is used to enable the data repositories to reliably identify data being requested. When a data request is received, each silo evaluates whether it has all or a portion of the data being requested and responds to requests when it has the data. Requests for data are implemented by broadcasting a cryptographic hash data identifier of the data file needed. The data identifier is used by a silo to determine which data to receive and store.

Abstract: Representing a number of assets on an originating computer begins with selecting the assets to be represented. Cryptographic hash asset identifiers are generated; each of the asset identifiers is computed using the contents of a particular asset. The asset identifier is a content-based or content-addressable asset name for the asset and is location independent. An asset list is generated that includes the asset identifiers computed from the assets. A cryptographic hash asset list identifier is generated that is computed from the asset list. The asset list identifier is stored for later retrieval. The assets selected are also stored for safekeeping either locally or on a computer network. In the event of loss of the files from the originating computer, the asset list identifier is retrieved. Using the asset list identifier, the original asset list is found and retrieved from its safe location.

Abstract: Representing a number of assets on an originating computer begins with selecting the assets to be represented. Cryptographic hash asset identifiers are generated; each of the asset identifiers is computed using the contents of a particular asset. The asset identifier is a content-based or content-addressable asset name for the asset and is location independent. An asset list is generated that includes the asset identifiers computed from the assets. A cryptographic hash asset list identifier is generated that is computed from the asset list. The asset list identifier is stored for later retrieval. The assets selected are also stored for safekeeping either locally or on a computer network. In the event of loss of the files from the originating computer, the asset list identifier is retrieved. Using the asset list identifier, the original asset list is found and retrieved from its safe location.

Abstract: One embodiment is directed to a method of segregating one or more content addressable storage systems into a plurality of virtual pools. The virtual pools can be allocated to different content sources and/or can be assigned to different storage system capabilities. Another embodiment is directed to transmitting with an input/output request for a content unit information specifying at least one storage capability to be applied to the content unit, and/or receiving such an I/O and implementing the specified storage system capabilities. Another embodiment is directed to extracting from an I/O request from a source information relating to an impact of the I/O on at least one characteristic of the content units stored on a CAS system from the source.

Abstract: Access to content addressable data on a network is facilitated using digital information storing devices or data repositories (“silos”) that monitor broadcast data requests over the network. A number of silos automatically monitor both data requests and data itself that are broadcast over a network. The silos selectively store data. Each silo responds to data requests broadcast over the network with data the silo has previously intercepted. A content addressable file scheme is used to enable the data repositories to reliably identify data being requested. When a data request is received, each silo evaluates whether it has all or a portion of the data being requested and responds to requests when it has the data. Requests for data are implemented by broadcasting a cryptographic hash data identifier of the data file needed. The data identifier is used by a silo to determine which data to receive and store.

Abstract: Access to content addressable data on a network is facilitated using digital information storing devices or data repositories (“silos”) that monitor broadcast data requests over the network. A number of silos automatically monitor both data requests and data itself that are broadcast over a network. The silos selectively store data. Each silo responds to data requests broadcast over the network with data the silo has previously intercepted. A content addressable file scheme is used to enable the data repositories to reliably identify data being requested. When a data request is received, each silo evaluates whether it has all or a portion of the data being requested and responds to requests when it has the data. Requests for data are implemented by broadcasting a cryptographic hash data identifier of the data file needed. The data identifier is used by a silo to determine which data to receive and store.

Abstract: An algorithm (such as the MD5 hash function) is applied to a file to produce an intrinsic unique identifier (IUI) for the file (or message digest). The file is encrypted using its IUI as the key for the encryption algorithm. An algorithm is then applied to the encrypted file to produce an IUI for the encrypted file. The encrypted file is safely stored or transferred within a network and is uniquely identifiable by its IUI. The encrypted file is decrypted using the IUI of the plaintext file as the key. The IUI serves as both a key to decrypt the file and also as verification that the integrity of the plaintext file has not been compromised. IUIs for any number of such encrypted files may be assembled into a descriptor file that includes meta data for each file, the IUI of the plaintext file and the IUI of the encrypted file. An algorithm is applied to the descriptor file to produce an IUI for the descriptor file.

Abstract: Access to content addressable data on a network is facilitated using digital information storing devices or data repositories (“silos”) that monitor broadcast data requests over the network. A number of silos automatically monitor both data requests and data itself that are broadcast over a network. The silos selectively store data. Each silo responds to data requests broadcast over the network with data the silo has previously intercepted. A content addressable file scheme is used to enable the data repositories to reliably identify data being requested. When a data request is received, each silo evaluates whether it has all or a portion of the data being requested and responds to requests when it has the data. Requests for data are implemented by broadcasting a cryptographic hash data identifier of the data file needed. The data identifier is used by a silo to determine which data to receive and store.

Abstract: Representing a number of assets on an originating computer begins with selecting the assets to be represented. Cryptographic hash asset identifiers are generated; each of the asset identifiers is computed using the contents of a particular asset. The asset identifier is a content-based or content-addressable asset name for the asset and is location independent. An asset list is generated that includes the asset identifiers computed from the assets. A cryptographic hash asset list identifier is generated that is computed from the asset list. The asset list identifier is stored for later retrieval. The assets selected are also stored for safekeeping either locally or on a computer network. In the event of loss of the files from the originating computer, the asset list identifier is retrieved. Using the asset list identifier, the original asset list is found and retrieved from its safe location.

Abstract: An algorithm (such as the MD5 hash function) is applied to a file to produce an intrinsic unique identifier (IUI) for the file (or message digest). The file is encrypted using its IUI as the key for the encryption algorithm. An algorithm is then applied to the encrypted file to produce an IUI for the encrypted file. The encrypted file is safely stored or transferred within a network and is uniquely identifiable by its IUI. The encrypted file is decrypted using the IUI of the plaintext file as the key. The IUI serves as both a key to decrypt the file and also as verification that the integrity of the plaintext file has not been compromised. IUIs for any number of such encrypted files may be assembled into a descriptor file that includes meta data for each file, the IUI of the plaintext file and the IUI of the encrypted file. An algorithm is applied to the descriptor file to produce an IUI for the descriptor file.

Abstract: A environment and method are provided for increasing the storage capacity of a data storage environment. Additional storage clusters may be added to the storage environment without affecting the performance of each individual storage cluster. When data is written to the storage environment, a selection may be made as to which storage cluster is to store the data. When data is read from the storage environment, it may be determined which storage cluster stores the data and the data may be retrieved from that storage cluster.

Abstract: Representing a number of assets on an originating computer begins with selecting the assets to be represented. Cryptographic hash asset identifiers are generated; each of the asset identifiers is computed using the contents of a particular asset. The asset identifier is a content-based or content-addressable asset name for the asset and is location independent. An asset list is generated that includes the asset identifiers computed from the assets. A cryptographic hash asset list identifier is generated that is computed from the asset list. The asset list identifier is stored for later retrieval. The assets selected are also stored for safekeeping either locally or on a computer network. In the event of loss of the files from the originating computer, the asset list identifier is retrieved. Using the asset list identifier, the original asset list is found and retrieved from its safe location.

Abstract: An algorithm (such as the MD5 hash function) is applied to a file to produce an intrinsic unique identifier (IUI) for the file (or message digest). The file is encrypted using its IUI as the key for the encryption algorithm. An algorithm is then applied to the encrypted file to produce an IUI for the encrypted file. The encrypted file is safely stored or transferred within a network and is uniquely identifiable by its IUI. The encrypted file is decrypted using the IUI of the plaintext file as the key. The IUI serves as both a key to decrypt the file and also as verification that the integrity of the plaintext file has not been compromised. IUIs for any number of such encrypted files may be assembled into a descriptor file that includes meta data for each file, the IUI of the plaintext file and the IUI of the encrypted file. An algorithm is applied to the descriptor file to produce an IUI for the descriptor file.

Abstract: An algorithm (such as the MD5 hash function) is applied to a file to produce an intrinsic unique identifier (IUI) for the file (or message digest). The file is encrypted using its IUI as the key for the encryption algorithm. An algorithm is then applied to the encrypted file to produce an IUI for the encrypted file. The encrypted file is safely stored or transferred within a network and is uniquely identifiable by its IUI. The encrypted file is decrypted using the IUI of the plaintext file as the key. The IUI serves as both a key to decrypt the file and also as verification that the integrity of the plaintext file has not been compromised. IUIs for any number of such encrypted files may be assembled into a descriptor file that includes meta data for each file, the IUI of the plaintext file and the IUI of the encrypted file. An algorithm is applied to the descriptor file to produce an IUI for the descriptor file.

Abstract: One embodiment is a system for locating content on a storage system, in which the storage system provides a location hint to the host of where the data is physically stored, which the host can resubmit with future access requests. In another embodiment, an index that maps content addresses to physical storage locations is cached on the storage system. In yet another embodiment, intrinsic locations are used to select a storage location for newly written data based on an address of the data. In a further embodiment, units of data that are stored at approximately the same time having location index entries that are proximate in the index.