Methods and apparatus for marking writes on a write-protected failed device to avoid reading stale data in a RAID storage system
US8812901B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 2011 |
| Grant date | Aug 19, 2014 |
| Priority date | — |
| Expiry date | Aug 2, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2211/1059
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for improved building of a hot spare storage device in a RAID storage system while avoiding reading of stale data from a failed storage device. In the recovery mode of the failed device, all data is write protected on the failed device. A RAID storage controller may copy as much readable data as possible from the failed device to the hot spare storage device. Unreadable data may be rebuilt using redundant information of the logical volume. Write requests directed to the failed device cause the addressed logical block address (LBA) to be marked as storing stale data. When a read request is directed to such a marked LBA, the read request returns an error status from the failed device to indicate that the data is stale. The RAID controller then rebuilds the now stale data for that LBA from redundant information of the logical volume.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.