The contents of the files are distributed in a way that eliminates hot spots and provides balanced I/O across the disks.
Redundancy levels
A disk group can be created with one of three redundancy levels:
- Normal (2-way mirroring)
- High (3-way mirroring)
- External (do not use ASM mirroring)
the redundancy level determines the number of tolerated disk failures before the diskgroup is unmounted.