Reducing file system data unavailability window by adapting hierarchical recovery framework
First Claim
1. A method to reduce file system data unavailability upon detecting a fault in the file system, the file system including a hierarchy of objects, the hierarchy of objects stored on slices of a storage device group, the method comprising:
- creating a fault tree representative of the hierarchy of objects;
identifying within the fault tree a fault branch, the fault branch identified by an object of the hierarchy of objects producing the fault in the file system;
denying access by the file system to objects of the fault branch of the fault tree;
repairing objects in the hierarchy of objects identified by the fault branch of the fault tree; and
permitting access by the file system to objects in the hierarchy of objects identified by the fault branch of the fault tree.
9 Assignments
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Accused Products
Abstract
A storage processor isolates and classifies file system faults and inconsistencies to produce a fault tree for inline error recovery. The storage processor isolates the metadata objects or objects that have internal inconsistencies, the storage processor creates a fault tree to map the file system; or portion of the file system with the errors or inconsistencies and the metadata objects dependent upon those objects. Once the fault having been mapped, determine the complexity of recovering the branch of the fault tree with the error. If the error is not too complex, performing recovery of the metadata objects online otherwise taking the system offline for file system recovery.
17 Citations
22 Claims
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1. A method to reduce file system data unavailability upon detecting a fault in the file system, the file system including a hierarchy of objects, the hierarchy of objects stored on slices of a storage device group, the method comprising:
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creating a fault tree representative of the hierarchy of objects; identifying within the fault tree a fault branch, the fault branch identified by an object of the hierarchy of objects producing the fault in the file system; denying access by the file system to objects of the fault branch of the fault tree; repairing objects in the hierarchy of objects identified by the fault branch of the fault tree; and permitting access by the file system to objects in the hierarchy of objects identified by the fault branch of the fault tree. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A storage system that reduces file system data unavailability, the system comprising:
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a storage device group providing persistent storage of file system data, the file system data including a hierarchy of objects, the hierarchy of objects stored onto slices of the storage device group; a controller circuit constructed and configured to; detect a fault; create a fault tree representative of the hierarchy of objects; identify within the fault tree a fault branch, the fault branch identified by an object of the hierarchy of objects producing the fault in the file system; deny access by the file system to objects of the hierarchy of objects identified by the fault branch of the fault tree; repair objects in the hierarchy of objects identified by the fault branch of the fault tree; and permit access by the file system to objects of the hierarchy of objects identified by the fault branch of the fault tree. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A non-transitory computer readable storage medium with a computer program stored thereon, the computer program executed by a processor to perform the method of reducing file system data unavailability upon detecting a fault in the file system, the file system including a hierarchy of objects, the hierarchy of objects stored on slices of a storage device group, the method comprising:
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creating a fault tree representative of the hierarchy of objects; identifying within the fault tree a fault branch, the fault branch identified by an object of the hierarchy of objects producing the fault in the file system; denying access by the file system to objects of the fault branch of the fault tree; repairing objects in the hierarchy of objects identified by the fault branch of the fault tree; and permitting access by the file system of objects in the hierarchy of objects identified by the fault branch of the fault tree. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A method to increase file system data availability upon detecting a fault in a file system including a hierarchy of objects, the hierarchy of objects being stored on slices of a storage device group, the method comprising:
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creating a fault tree representative of the hierarchy of objects; identifying within the fault tree a fault branch, the fault branch being identified by an object of the hierarchy of objects producing the fault in the file system; denying access by the file system to objects of the fault branch of the fault tree; repairing objects of the fault branch of the fault tree; and permitting access by the file system to the objects of the fault branch of the fault tree; wherein repairing objects of the fault branch of the fault tree includes; creating a recovery plan to bring a first set of objects of the fault branch of the fault tree into consistent reference to a second set of objects of the fault branch of the fault tree; setting a numeric value indicating a complexity level of the recovery plan; upon the numeric value indicating the complexity level of the recovery plan being less than or equal to a predefined complexity level; recovering valid values of the objects of the fault branch of the fault tree; and allowing access by the file system to the objects of the fault branch of the fault tree; and upon the numeric value indicating the complexity level of the recovery plan being greater than the predefined complexity level; saving the fault tree and the recovery plan to a save area; and marking the file system for offline recovery.
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Specification