5
Figure 6 RAID 1
Application scenarios
RAID 1 is useful when high performance and data protection are more important than the cost of
physical drives.
Advantages
Has the highest security performance among all RAID methods.
No data is lost as long as no failed drive is mirrored to another failed drive.
Up to half of the physical drives in the array can fail.
Disadvantages
This method is expensive as it needs many drives for fault tolerance.
Only half of the total drive capacity is usable for data storage.
RAID 1E
RAID 1E enhances RAID 1. RAID 1E not only mirrors data but also stripes data. RAID 1E can
mirror data for an odd number of drives, as shown in Figure 7.