|1. Disk mirroring is a two-disk system which is attached to a host controller. One of the disks will serve as the mirror image of the other. When data is written to one disk, it is also written to the other disk. Both disks will contain exactly the same information.
Note: Disk mirroring protects data against hardware failure. If one fails, the other can supply the user data without problem.
2. Disk mirroring is the duplication of data on separate disks in real time to ensure its continuous availability, currency and accuracy. Disk mirroring can function as a disaster recovery solution by performing the mirroring remotely. True mirroring will enable a zero recovery point objective. Depending on the technologies used, mirroring can be performed synchronously, asynchronously, semi-synchronously, or point-in-time. SIMILAR TERMS: File Shadowing, Data Replication, Journaling.
(Source: Disaster Recovery Institute International / Disaster Recovery Journal - DRII/DRJ)
(Source: ENISA - the European Network and Information Security Agency. BCM & Resilience Glossary)