Emc Corporation

Emc IP Holding Company LLC

Tom Teugels

Jan Van Riel

Stephen J Todd

Michael Kilian

Paul Carpentier

Kim Marivoet

Frank Matthys

Carl D'Halluin

Mark A O'Connell

Mark Avery

Francis Martens

Jan Bruyndonckx

Carl D′Halluin

Christophe Bouhon

Paul R Carpentier

Jan F Van Riel

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. The plaintext descriptor file is then encrypted using the descriptor file IUI as a key for the encryption algorithm. An algorithm is applied to the encrypted descriptor file to produce an IUI for the encrypted descriptor file. The IUI of the encrypted descriptor file is a location-independent identifier to locate the encrypted descriptor file. A flattened descriptor file includes the IUIs of encrypted data files and the IUI of the encrypted descriptor file. An algorithm is applied to the flattened descriptor file to produce its own IUI.

System and method for secure storage, transfer and retrieval of content addressable information

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.

Methods and apparatus for increasing data storage capacity

A system and method are provided for retention of data on a storage system. An application program provides the storage system with data to be stored on the storage system. The application program also provides the storage system with a retention period that indicates a period of time for which the data may not be deleted. When the storage system receives a request to delete the data, it first evaluates the retention period associated with that data to determine if the retention period has expired. If the retention period has not expired, the storage system denies the request to delete the data.

Method and apparatus for data retention in a storage system

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).

Granting access to a content unit stored on an object addressable storage system

Managing data on a federated CAS system includes determining a group of objects to be stored on a single CAS system of the federated CAS system, obtaining a cookie corresponding a particular one of the CAS systems of the federated CAS system in response to initially writing at least one object of the group of objects, where the at least one object is written to the particular one of the CAS systems, and providing the cookie in connection with writing objects of the group of objects following initially writing at least one object of the group of objects. The cookie causes the objects to be written to the particular one of the CAS systems. The cookie may be provided by at least one router that maintains the federated CAS system, which may be separate from both a processing device and the particular one of the CAS systems.

Method and system of providing object location metadata cookies in a federated content addressable storage system

In one aspect, two ways of accessing a content unit stored on a CAS are provided, wherein the content unit has a content address that is computed based, at least in part, on at least a portion of its content. A first interface is provided to a file system in which the content unit is logically stored as a logical unit identified by a logical identifier, wherein the content unit is accessed in response to a request to the first interface to access the logical unit and identifying the content unit via the logical identifier. A second interface is provided through which the content unit can be accessed via the content address, wherein the content unit is accessed in response to a request to the second interface to access the content unit and identifying the content unit by the content address.

Methods and apparatus for allowing access to content

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. A silo includes a network interface, a digital asset collector, an asset request list, asset storage, an asset identifier processor and an asset supplier. The asset identifier processor computes a cryptographic hash asset identifier for a received asset and compares it to an asset identifier on its asset request list to verify it has the correct asset. A hash of a list of assets is also computed and broadcast over the network. When the hash of the list of assets is received by a silo, it places all the assets in its asset request list.

Access to content addressable data over a network

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. Another embodiment is directed to storing information for content identifying the source and/or reading information associated with a stored content unit and determining based at least in part thereon, at least one characteristic of the content units stored from a source.

Methods and apparatus for accessing content in a virtual pool on a content addressable storage system

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.

Methods and apparatus for managing deletion of data

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.

Methods and apparatus for selecting a storage zone for a content unit

One aspect involves mounting a file system stored on a CAS system. The file system has a directory structure that includes a plurality of directories arranged in a hierarchy and including a root directory at the top of the hierarchy. Each of the directories is represented by a content unit stored on the CAS system, the content unit having a content address that is computed based, at least in part, on at least a portion of the content of the content unit. The file system is mounted by specifying the content address of the content unit that represents the root directory and determining the file system to be mounted based on the content address of the content unit that represents the root directory.

Methods and apparatus for mounting a file system

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. The asset identifiers from the retrieved asset list are used to find and retrieve the individual assets from their backup locations. The assets are verified by recomputing the cryptographic hash asset identifier for each asset retrieved and comparing it to the asset identifier from the asset list. The MD5 algorithm is used for the cryptographic hash function. Assets are retrieved using a multicast protocol. A series of importer programs searches for assets to retrieve in progressively more remote locations. Assets are retrieved whole or in segments.

Growing community of inventors

Schoten, Belgium

Tom Teugels