Virtual memory device (VMD) application/driver with dual-level interception for data-type splitting, meta-page grouping, and diversion of temp files to ramdisks for enhanced flash endurance
US8954654B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2012 |
| Grant date | Feb 10, 2015 |
| Priority date | — |
| Expiry date | Jul 11, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/765
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A Virtual-Memory Device (VMD) driver and application execute on a host to increase endurance of flash memory attached to a Super Enhanced Endurance Device (SEED) or Solid-State Drive (SSD). Host accesses to flash are intercepted by the VMD driver using upper and lower-level filter drivers and categorized as data types of paging files, temporary files, meta-data, and user data files, using address ranges and file extensions read from meta-data tables. Paging files and temporary files are optionally written to flash. Full-page and partial-page data are grouped into multi-page meta-pages by data type before storage by the SSD. ramdisks and caches for storing each data type in the host DRAM are managed and flushed to the SSD by the VMD driver. Write dates are stored for pages or blocks for management functions. A spare/swap area in DRAM reduces flash wear. Reference voltages are adjusted when error correction fails.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.