ASM supports 3 types of redundancy.
1.external redundancy
2.normal redundancy
3.high redundancy
External redundancy means no mirroring at oracle ASM level.
Normal redundancy is also called as 2-way mirroring.
In order to create a diskgroup with normal redundancy minimum number of disks/partitions are required are 2.
High redundancy is also called as 3-way mirroring. In order to create a diskgroup with high redundancy, minimum number of disks required are 3.
