Redundant, asymmetrically parallel disk cache for a data storage system
US6243795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1998 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Aug 4, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/312
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data storage system includes redundant write caches, a disk controller and an array of disks. One of the redundant write caches is a primary write cache of RAM or NVRAM, and another is a backup write cache having a hybrid memory structure of a relatively small amount of NVRAM in combination with a cache-disk space mapped to disk. The cache-disk space may be located on a single disk within the disk array, or distributed over a number of the plurality of disks in the array. In one embodiment, the array of disks can may be configured as a RAID architecture. The data storage system of the present invention preferably employs a conventional, fast-write-fast-read primary write cache and a non-volatile, hybrid memory backup write cache. The redundant write caches are asymmetric since the primary write cache and the backup write cache have different sizes and structures. The system is relatively inexpensive since the amount NVRAM in the backup cache is relatively small, ranging from hundreds of KB to several MB, and the cost of the disk space for the cache-disk space is significantly less than a large amount of NVRAM. Advantageously, the caching arrangement of the present invention has a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.