Invention Grant
- Patent Title: Erasure coding repair availability
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Application No.: US16711513Application Date: 2019-12-12
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Publication No.: US11372738B2Publication Date: 2022-06-28
- Inventor: Song Guen Yoon , Dheeraj Raghavender Sangamkar , Emalayan Vairavanathan
- Applicant: NetApp, Inc.
- Applicant Address: US CA Sunnyvale
- Assignee: NetApp, Inc.
- Current Assignee: NetApp, Inc.
- Current Assignee Address: US CA Sunnyvale
- Agency: Haynes and Boone, LLP
- Main IPC: G06F11/20
- IPC: G06F11/20 ; G06F11/10 ; H03M13/15 ; H03M13/37

Abstract:
Distributed storage systems frequently use a centralized metadata repository that stores metadata in an eventually consistent distributed database. However, a metadata repository cannot be relied upon for determining which erasure coded fragments are lost because of a storage node(s) failures. Instead, when recovering a failed storage node, a list of missing fragments is generated based on fragments stored in storage devices of available storage nodes. A storage node performing the recovery sends a request to one or more of the available storage nodes for a fragment list. The fragment list is generated, not based on a metadata database, but on scanning storage devices for fragments related to the failed storage node. The storage node performing the recovery merges retrieved lists to create a master list indicating fragments that should be regenerated for recovery of the failed storage node(s).
Information query