Metadata paging mechanism tuned for variable write-endurance flash
US10318180B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2016 |
| Grant date | Jun 11, 2019 |
| Priority date | — |
| Expiry date | Aug 24, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/7207
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A storage array uses both high endurance SSDs and low endurance SSDs for metadata paging. Wear cost values are calculated for each page of metadata in cache. The wear cost values are used to select pages for swapping out of the cache to the SSDs. The wear cost values may be calculated as a function of a first term that is indicative of whether the respective page of metadata will be written to high endurance or low endurance SSDs; a second term that is indicative of likelihood of data associated with the respective pages of metadata that will possibly be changed due to a write; and a third term that is indicative of age of the respective page of metadata in the cache since most recent use. The terms may be estimated and independently weighted. The portion of cache allocated for the metadata may be increased to avoid exceeding DWPD targets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.