Abstract: Among other things, in one aspect, in general, a system for managing data in a data storage system includes a plurality of index nodes each storing a map of entries, each entry of the map including an identifier corresponding to a particular portion of data stored in the data storage system, and metadata indicating a location where the particular portion of data is stored in the data storage system, and one or more supernodes configured to return an identification of an index node that recently submitted a request for a particular identifier associated with at least one of the portions of data.

Abstract: In general, in one aspect, a method for managing data in a data storage system includes receiving identifiers corresponding to different respective entries of a map stored in the data storage system, with a particular identifier corresponding to a particular entry of the map, the particular entry including a computed value corresponding to a particular portion of data stored in the data storage system and metadata indicating a location where the particular portion of data is stored in the data storage system, selecting, according to a first selection criterion, at least some of the identifiers for storage in a first portion of an index, and selecting, according to a second selection criterion, at least some of the identifiers for storage in a second portion of the index.

Abstract: Among other things, in one aspect, in general, a system for managing data in a data storage system includes a plurality of index nodes each storing a map of entries, each entry of the map including an identifier corresponding to a particular portion of data stored in the data storage system, and metadata indicating a location where the particular portion of data is stored in the data storage system, and one or more supernodes configured to return an identification of an index node that recently submitted a request for a particular identifier associated with at least one of the portions of data.

Abstract: Among other things, in one aspect, in general, a system for managing data in a data storage system includes a plurality of index nodes each storing a map of entries, each entry of the map including an identifier corresponding to a particular portion of data stored in the data storage system, and metadata indicating a location where the particular portion of data is stored in the data storage system, and one or more supernodes configured to return an identification of an index node that recently submitted a request for a particular identifier associated with at least one of the portions of data.

Abstract: In one aspect, in general, a method for managing data includes receiving, at a data deduplication engine of a computer system, data to be stored in a data storage system, computing a first value corresponding to at least one portion of the received data, determining that the first value matches a second value stored in a collection of identifiers, each identifier corresponding to a particular portion of data stored in the data storage system, each identifier comprising a computed value corresponding to the particular portion of data and including metadata indicating a location where the particular portion of data is being stored in the data storage system, and based on the determination that the first value matches a second value stored in the collection of identifiers, reallocating one or more physical locations from corresponding one or more virtual locations to different respective one or more virtual locations.

Abstract: In general, in one aspect, a method for managing data in a data storage system includes receiving identifiers corresponding to different respective entries of a map stored in the data storage system, with a particular identifier corresponding to a particular entry of the map, the particular entry including a computed value corresponding to a particular portion of data stored in the data storage system and metadata indicating a location where the particular portion of data is stored in the data storage system, selecting, according to a first selection criterion, at least some of the identifiers for storage in a first portion of an index, and selecting, according to a second selection criterion, at least some of the identifiers for storage in a second portion of the index.

Abstract: In one aspect, in general, a method for managing data in a data storage system comprises receiving data to be stored in the data storage system, computing values corresponding to different respective portions of the received data, generating identifiers corresponding to different respective portions of the received data, with an identifier corresponding to a particular portion of data including the computed value corresponding to the particular portion of data and metadata indicating a location where the particular portion of data is being stored in the data storage system, and storing at least some of the identifiers in an index until the index reaches a predetermined size.

Abstract: Managing data in a data storage system includes: receiving data to be stored in the data storage system; computing values corresponding to different respective portions of the received data; generating identifiers corresponding to different respective portions of the received data, with an identifier corresponding to a particular portion of data including the computed value corresponding to the particular portion of data and metadata indicating a location where the particular portion of data is being stored in the data storage system; storing at least some of the identifiers in an index until the index reaches a predetermined size; and in response to determining that a first identifier corresponding to a first portion of data, received after the index reached the predetermined size, was not already stored in the index before the first portion of data was received, storing the first identifier in the index and designating for removal at least a second identifier corresponding to a second portion of data to be

Abstract: A method for organizing a storage system that is scalable and fault tolerant, the method including grouping together a number D of storage elements to form the storage system, where D is more than one, constructing a storage assignment table that includes table entries, computing, for each of the storage elements, an available capacity that depends on constraints on the placement of redundant data within the storage system, summing the available capacities to form a total available capacity for the storage system; and assigning the table entries in the storage assignment table to each identify one of the storage elements, wherein the available capacity of each of the storage elements is its effective storage capacity when used as part of the storage system, wherein not all of the D storage elements that form the storage system have the same available capacity, and wherein the fraction of all table entries that identify a one of the storage elements depends upon its fraction of the total available capacity.

Abstract: A method for organizing a storage system that is scalable and fault tolerant, the method including grouping together a number D of storage elements to form the storage system, where D is more than one, constructing a storage assignment table that includes table entries, computing, for each of the storage elements, an available capacity that depends on constraints on the placement of redundant data within the storage system, summing the available capacities to form a total available capacity for the storage system; and assigning the table entries in the storage assignment table to each identify one of the storage elements, wherein the available capacity of each of the storage elements is its effective storage capacity when used as part of the storage system, wherein not all of the D storage elements that form the storage system have the same available capacity, and wherein the fraction of all table entries that identify a one of the storage elements depends upon its fraction of the total available capacity.