RAID 1 writes and reads identical data to pairs of drives. This process is often called data mirroring and it’s a primary function is to provide redundancy.
If any of the disks in the array fails, the system can still access data from the remaining disk(s). Once the faulty disk is replaced with a new one, the data is copied to it from the functioning disk(s) to rebuild the array.
RAID 1 is the easiest way to create failover storage.
- Minimum number of disks: 2
- Pros: Fault tolerance and easy data recovery. Increased read performance.
- Cons: Lower usable capacity. Higher cost per megabyte (double the amounts of drives is required to achieve desired capacity).
- Business use: Standard application servers where data redundancy and availability are important.