Dustin M. Hendrickson

Bio: Dustin M. Hendrickson is an academic researcher from IBM. The author has contributed to research in topics: Computer data storage & Fault (power engineering). The author has an hindex of 7, co-authored 12 publications receiving 1250 citations.

Metadata management system for an information dispersed storage system

Abstract: Briefly, the present invention relates to an information dispersal sytem in which original data to be stored is separated into a number of data 'slices' in such a manner that the data in each subset is less usable or less recognizable or completely unusable or completely unrecognizable by itself except when combined with some or all of the other data subsets. These data subsets are stored on separate storage devices as a way of increasing privacy and security. In accordance with an important aspect of the invention, a metadata management system stores and indexes user files across all of the storage nodes. A number of applications run on the servers supporting these storage nodes and are responsible for controlling the metadata. Metadata is the information about the data, the data slices or data subsets and the way in which these data subsets are dispersed among different storage nodes running over the network. As used herein, metadata includes data source names, their size, last modification date, authentication information etc. This information is required to keep track of dispersed data subsets among all the nodes in the system. Every time new data subsets are stored and old ones are removed from the storage nodes, the metadata is updated. In accordance with an important aspect of the invention, the metadata management system stores metadata for dispersed data where: the dispersed data is in several pieces; the metadata is in a separate dataspace from the dispersed data. Accordingly, the metadata management system is able to manage the metadata in a manner that is computationally efficient relative to known systems in order to enable broad use of the invention using the types of computers generally used by businesses, consumers and other organizations currently.

Rebuilding data on a dispersed storage network

Abstract: A rebuilder application operates on a dispersed data storage grid and rebuilds stored data segments that have been compromised in some manner. The rebuilder application actively scans for compromised data segments, and is also notified during partially failed writes to the dispersed data storage network, and during reads from the dispersed data storage network when a data slice is detected that is compromised. Records are created for compromised data segments, and put into a rebuild list, which the rebuilder application processes.

Ensuring data integrity on a dispersed storage grid

Abstract: An improved system is disclosed for ensuring the integrity of data stored on a dispersed data storage network. Checksums are used to ensure integrity of both data segments and data slices. Checksums appended to data slices are checked by receiving slice servers to ensure that no errors occurred during transmission. Slice servers also periodically recalculate checksums for stored data slices to ensure that data slices have not been corrupted during storage. Checksums appended to data segments are checked when data segments are read from the storage network.

Method and apparatus for rebuilding data in a dispersed data storage network

Abstract: A method begins by identifying a data slice requiring rebuilding to produce an identified data slice, wherein the identified data slice is one of a plurality of data slices that constitute a data segment and wherein each of the plurality of data slices is assigned for storage by a corresponding one of a plurality of data slice servers. The method continues by retrieving at least m number of data slices from at least m number of the plurality of data slice servers, wherein m data slices of the plurality of data slices enable reconstruction of the data segment, and wherein the at least m number of data slices does not include the identified data slice. The method continues by reconstructing the identified data slice from the at least m number of data slices to produce a rebuilt data slice. The method continues by writing the rebuilt data slice to the corresponding one of the plurality of data slice servers or to a new slice server.

Range based rebuilder for use with a dispersed data storage network

Abstract: A message is generated by a computer operating on a dispersed data storage network indicating the inaccessibility of a plurality of data slices. A rebuilder application operates on the dispersed data storage grid and rebuilds inaccessible data slices, including those identified by the message.

Smart access to a dispersed data storage network

Abstract: An improved system for accessing data within a distributed data storage network (“DDSN”) is disclosed. In a system implementing the disclosed invention, traffic is routed to individual slice servers within the DDSN in accordance with objective criteria as well as user-defined policies. In accordance with one aspect of the disclosed invention, when a data segment is written to a DDSN, the segment is divided into multiple data slices, which are simultaneously transmitted to different slice servers. In accordance with another aspect of the disclosed invention, when a data segment is read from a DDSN, a list of slice servers, each containing a data slice that could be used to reconstruct the requested data segment, is assembled, and sorted in accordance with a preference rating assigned to each of the slice servers. Sufficient data slices to reconstruct the data segment are then read in accordance with the preference ranking of the slice servers.

System for rebuilding dispersed data

Abstract: A digital data file storage system is disclosed in which original data files to be stored are dispersed using some form of information dispersal algorithm into a number of file “slices” or subsets in such a manner that the data in each file share is less usable or less recognizable or completely unusable or completely unrecognizable by itself except when combined with some or all of the other file shares. These file shares are stored on separate digital data storage devices as a way of increasing privacy and security. As dispersed file shares are being transferred to or stored on a grid of distributed storage locations, various grid resources may become non-operational or may operate below at a less than optimal level. When dispersed file shares are being written to a dispersed storage grid which not available, the grid clients designates the dispersed data shares that could not be written at that time on a Rebuild List. In addition when grid resources already storing dispersed data become non-available, a process within the dispersed storage grid designates the dispersed data shares that need to be recreated on the Rebuild List. At other points in time a separate process reads the set of Rebuild Lists used to create the corresponding dispersed data and stores that data on available grid resources.

Billing system for information dispersal system

Abstract: A billing process is disclosed for an information dispersal system or digital data storage system. The original data to be stored is separated into a number of data 'slices' or shares (22, 24, 26, 28, 30, and 32). These data subsets are stored on separate digital data storage devices (34, 36, 38, 40, 42, and 44) as a way of increasing privacy and security. A set of metadata tables are created, separate from the dispersed file share storage, to maintain information about the original data size of each block, file or set of file shares dispersed on the grid.

Block based access to a dispersed data storage network

Abstract: A block-based interface to a dispersed data storage network is disclosed. The disclosed interface accepts read and write commands from a file system resident on a user's computer and generates network commands that are forwarded to slice servers that form the storage component of the dispersed data storage network. The slice servers then fulfill the read and write commands.

Virtualized data storage vaults on a dispersed data storage network

Abstract: A system, method, and apparatus for implementing a plurality of dispersed data storage networks using a set of slice servers are disclosed. A plurality of information records are maintained, with each information record corresponding to a dispersed data storage network. The information record maintains what slice servers are used to implement the dispersed data storage network, as well as other information needed to administer a DDSN, such as the information dispersal algorithm used, how data is stored, and whether data is compressed or encrypted.