Abstract: Some embodiments are directed to a technique for storing and/or locating content units stored on an object addressable storage (OAS) system, wherein each content unit is identified by an object identifier. The OAS system may comprise a plurality of zones, each of which stores content units. A mapping process may be defined that maps object identifiers for content units to zones on the OAS system. Thus, the storage location for a content unit on the OAS system may be the zone on the OAS system to which the object identifier for the content unit maps.

Abstract: Aspects of the invention relate to sharing content stored on an object addressable storage (OAS) system among a plurality of users of the OAS system and authenticating users to an OAS system. In some embodiments, a user may store content units on the OAS system and control access by other users to these content units. In some embodiments, when a user grants one or more other users access to a content unit stored on the OAS system, the OAS system may send a notification of grant of access to the other user(s).

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: Aspects of the invention relate to sharing content stored on an object addressable storage (OAS) system among a plurality of users of the OAS system and authenticating users to an OAS system. In some embodiments, a user may store content units on the OAS system and control access by other users to these content units. In some embodiments, when a user grants one or more other users access to a content unit stored on the OAS system, the OAS system may send a notification of grant of access to the other user(s).

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: 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. The prefetch policy imposes a limit on at least one prefetch operation. The limit is selected from the group consisting of: a total number of content units to be prefetched; a time range during which content units were stored to qualify as prefetch candidates; and a total volume of content to be prefetched.

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 at least one edge device. The cache has a replacement policy that selects from among the content units in the cache based upon at least one replacement criterion selected from the group consisting of: an identity of a source that wrote an evaluated content unit; when the replacement is performed subsequent to a request to access at least one content unit, an identity of a requestor that issued the request; a size of an evaluated content unit; a content type of an evaluated content unit; and when metadata was written along with an evaluated content unit, the substance of the metadata.

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: 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: 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 (OAS) system that stores a plurality of content units and provides an interface that enables content units to be accessed via object identifiers. The at least one edge device is configured to access at least some of the content units. At least one cache is configured to be disposed logically between the core and the at least one edge device and to temporarily store a subset of the content units. The at least one cache is further configured to have a limit on a maximum number of content units that can be stored on the at least one cache simultaneously.

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 has 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: 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: 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 at least one edge device. The cache has a prefetch policy that selects from among the content units based upon at least one prefetch criterion selected from the group consisting of: a source that wrote an evaluated content unit; a size of an evaluated content unit; a content type of an evaluated content unit; when the prefetch is performed subsequent to a request to access at least one of the plurality of content units, an identity of the requestor; when the prefetch is performed subsequent to a request to access at least one of the content units stored at a first time, proximity of a time at which an evaluated content unit was stored relative to the first time; and metadata written with the evaluated 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 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 directed to a method for use in a computer system comprising at least first and second computers, wherein the first provides content addressable storage. A request to access a unit of data stored by the first computer is issued by the second computer and received by the first. In one embodiment, the unit of data comprises a first identifier identifying at least one digital asset and metadata relating to the at least one digital asset, and the request identifies the unit of data via a second identifier based, at least in part, on the content of the unit of data. In another embodiment, a request to access a unit of data is sent from a second computer and received at a first computer and identifies the unit of data via a content identifier based, at least in part, on the content of the unit of data. The content identifier is the only identifier that can be used in communication between the first and second computers to identify the unit of data.

Abstract: Techniques for managing the storing of a digital asset by a first computer in a computer system that further comprises a second computer. The first computer receives a communication from the second computer including the digital asset, determines whether the digital asset has been stored by the first computer, and when it has not, stores a copy of the digital asset. The digital asset is identified by a first identifier based, at least in part, on its content. In one embodiment, the first identifier is the only identifier that can be used to identify the digital asset in communication between the first and second computers. In another embodiment, the computer system further stores a unit of data comprising the first identifier and metadata relating to the digital asset.