Redundant data assigment in a data storage system
2 Assignments
0 Petitions
Accused Products
Abstract
The present invention provides techniques for assignment and layout of redundant data in data storage system. In one aspect, the data storage system stores a number M of replicas of the data. Nodes that have sufficient resources available to accommodate a requirement of data to be assigned to the system are identified. When the number of nodes is greater than M, the data is assigned to M randomly selected nodes from among those identified. The data to be assigned may include a group of data segments and when the number of nodes is less than M, the group is divided to form a group of data segments having a reduced requirement. Nodes are then identified that have sufficient resources available to accommodate the reduced requirement. In other aspects, techniques are providing for adding a new storage device node to a data storage system having a plurality of existing storage device nodes and for removing data from a storage device node in such a data storage system.
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Citations
50 Claims
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1-17. -17. (canceled)
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18. A method of assigning data to storage device nodes in a data storage system wherein the data storage system stores a number M of replicas of the data, the method comprising dividing the data into a plurality of groups of segments and for each group of segments, identifying nodes that have sufficient resources available to accommodate a requirement of the data, the requirement including at least one of a reliability requirement, a capacity requirement and a performance requirement, and when a number of nodes identified by said identifying is greater than M, assigning the data to M randomly selected nodes from among those identified and when the number of nodes is equal to M, assigning the data to the M identified nodes and when the number of nodes is less than M, dividing the group of data segments thereby forming a group of data segments having a reduced requirement and identifying nodes that have sufficient resources available to accommodate the reduced requirement and the method further comprising adding a new storage device node to the data storage system including identifying an existing node that is heavily loaded in comparison to other ones of existing nodes;
- moving data stored at the identified existing node to the new node; and
determining whether the new node is sufficiently loaded in comparison the existing nodes and when the new node is not sufficiently loaded, repeating said steps of identifying and moving until the new node is sufficiently loaded.
- moving data stored at the identified existing node to the new node; and
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19-25. -25. (canceled)
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26. A method for adding a new storage device node to a data storage system having a plurality of existing storage device nodes for storing redundant data, the method comprising steps of:
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identifying an existing node that is heavily loaded in comparison to other ones of the existing nodes;
moving data stored at the identified existing node to the new node; and
determining whether the new node is sufficiently loaded in comparison the existing nodes and when the new node is not sufficiently loaded, repeating said steps of identifying and moving until the new node is sufficiently loaded. - View Dependent Claims (27, 28, 29, 30, 31)
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32. (canceled)
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33. A method for removing data from a storage device node in a data storage system for storing redundant data, the data storage system having a plurality of storage device nodes, the method comprising steps of:
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selecting data from the storage device node from which data is to be removed;
identifying other nodes of the data storage system having sufficient resources available to accommodate a requirement of the data;
moving the data to a randomly selected node from among those identified; and
repeating said steps of selecting, identifying and moving until the storage device node to be removed is empty. - View Dependent Claims (34, 35, 36, 37, 38)
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39-41. -41. (canceled)
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42. A method for removing data from a storage device node in a data storage system for storing redundant data, the data storage system having a plurality of storage device nodes, the method comprising steps of:
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selecting data from the storage device node from which data is to be removed;
randomly selecting at least one other node in the data storage system;
determining whether the at least one other randomly selected node has sufficient resources available to accommodate a requirement of the data;
moving the data to one of the randomly selected nodes having sufficient resources available to accommodate a requirement of the data; and
repeating said steps of selecting data, randomly selecting, determining and moving until the storage device node to be removed is empty. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49)
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50-53. -53. (canceled)
Specification