Advantages : One Write or two Reads possible per mirrored pair. Twice the Read transaction rate of single disks, same Write transaction rate as single disks. 100% redundancy of data means no rebuild is necessary in case of a disk failure, just a copy to the replacement disk. Transfer rate per block is equal to that of a single disk Under certain circumstances, RAID 1 can sustain multiple simultaneous drive failures. Simplest RAID storage subsystem design.

Disadvantages : Highest disk overhead of all RAID types (100%) - inefficient. Typically the RAID function is done by system software, loading the CPU/Server and possibly degrading throughput at high activity levels. Hardware implementation is strongly recommended. May not support hot swap of failed disk when implemented in "software".

Recommended Use : Accounting. Payroll. Financial. Any application requiring very high availability.