Storage device with inline address indirection metadata storage
US8892817B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 2011 |
| Grant date | Nov 18, 2014 |
| Priority date | — |
| Expiry date | Jan 7, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/012
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods are described that allow disk drives, such as shingle-written magnetic recording (SMR) drives, to recover an Indirection Address Table mapping of LBAs to PBAs after an emergency power off (EPO). Indirection Address Table (IAT) snapshots are periodically written inline with user data stores, and in one embodiment Cumulative Delta Lists (CDLs) with incremental address update information are stored between snapshots. In an embodiment of the invention, when an imminent loss of power is detected, the current CDL, covering IAT updates not yet written to disk, is saved to a nonvolatile memory. The IAT snapshots combined with the set of CDLs provide the information needed to recreate the current Indirection Address Table when power is restored after an emergency power loss. In an alternative embodiment the CDL is obviated by including metadata in the sector that encodes the address indirection mapping and the last snapshot ID.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.