You’re installing two new hard drives into your network attached storage device. Your director asks that they be put into a RAID solution that offers redundancy over performance
Which would you use?
a. RAID 0
b. RAID 1
c. RAID 5
d. RAID
e. RAID 10
The Correct Answer and Explanation is :
The correct answer is b. RAID 1.
Explanation:
RAID (Redundant Array of Independent Disks) is a data storage virtualization technology that combines multiple physical disks into a single logical unit. There are different RAID levels, each providing varying levels of performance, redundancy, and fault tolerance.
In your scenario, the goal is to ensure redundancy over performance, meaning that you want the system to be fault-tolerant—i.e., capable of surviving the failure of one or more hard drives without data loss.
Here’s a breakdown of the RAID options:
- RAID 0 (Striping):
- Performance-focused: RAID 0 splits data evenly across two or more disks, which increases read and write speeds.
- No redundancy: If one disk fails, all data is lost, making it unsuitable when redundancy is required.
- RAID 1 (Mirroring):
- Redundancy-focused: RAID 1 duplicates the same data on two disks (mirroring). Each disk holds an exact copy of the other’s data.
- Fault tolerance: If one disk fails, the data remains accessible on the other disk. This is an ideal solution for redundancy because it ensures that data is preserved even if one hard drive is lost. However, it does not improve performance (it may even slightly reduce performance due to the mirroring process), but it is the best option for redundancy.
- RAID 5 (Striping with Parity):
- Balanced solution: RAID 5 uses both striping (to improve performance) and parity (to provide redundancy). It requires a minimum of three disks. Parity information is distributed across the disks, so if one disk fails, the data can be reconstructed using the parity data.
- Fault tolerance: RAID 5 offers redundancy, but since it involves multiple disks, it’s more complex than RAID 1 and does not offer as high a redundancy level as RAID 1 for two disks.
- RAID 10 (RAID 1+0):
- Combination of RAID 1 and RAID 0: RAID 10 combines mirroring (RAID 1) and striping (RAID 0). It provides high performance and redundancy but requires at least four disks.
- Redundancy and performance: RAID 10 is an excellent choice if both redundancy and performance are important, but it’s more complex and requires more disks than RAID 1.
Therefore, RAID 1 is the best option if your primary concern is redundancy, as it provides an exact copy of the data on each disk, ensuring data availability even if one disk fails.