Recovery from low space condition of an extent store
US9846539B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2016 |
| Grant date | Dec 19, 2017 |
| Priority date | — |
| Expiry date | Mar 5, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1435
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A technique recovers from a low space condition associated with storage space reserved in an extent store to accommodate write requests received from a host and associated metadata managed by a layered file system of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The write requests, including user data, are persistently recorded on non-volatile random access memory (NVRAM) prior to returning an acknowledgement to the host by a persistence layer of the storage I/O stack. Volume metadata managed by a volume layer of the layered file system is embodied as mappings from logical block addresses (LBAs) of a logical unit (LUN) accessible by the host to extent keys maintained by an extent store layer of the layered file system. Extent store metadata managed by the extent store layer is embodied as mappings from the extent keys to the storage locations of the extents on storage devices of storage arrays coupled to the nodes of the cluster. The space recovery technique accounts for storage space consumed in the extent store by user operations, i.e., write operations for the user data stored on the NVRAM at the persistence layer as well as the associated volum…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.