1. What is a RAID 5 Space Calculator?

Definition: This calculator estimates the usable storage space in a RAID 5 array based on the number of drives and their individual sizes.

Purpose: It helps IT professionals and system administrators plan storage capacity for RAID 5 configurations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Space \) — Usable storage space (TB)
• \( N \) — Number of drives in the array
• \( DriveSize \) — Capacity of each drive (TB)

Explanation: RAID 5 uses one drive's worth of space for parity data, so the total usable space is (number of drives - 1) multiplied by the drive size.

3. Importance of RAID 5 Space Calculation

Details: Proper space calculation ensures you allocate sufficient storage for your needs while maintaining fault tolerance through parity.

4. Using the Calculator

Tips: Enter the number of drives (minimum 3) and the size of each drive in TB. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why does RAID 5 need at least 3 drives?
A: RAID 5 requires a minimum of 3 drives to implement striping with distributed parity while still providing usable storage space.

Q2: What happens to the "lost" drive space?
A: One drive's worth of capacity is used for parity information that enables data recovery if a drive fails.

Q3: How does drive size affect the calculation?
A: All drives should ideally be the same size. If they differ, the calculation uses the smallest drive's size.

Q4: What's the maximum number of drives for RAID 5?
A: While technically unlimited, practical limits are usually around 16 drives due to performance and rebuild time considerations.

Q5: How does this compare to RAID 0 or RAID 1?
A: RAID 0 offers full capacity but no redundancy, RAID 1 offers half capacity with mirroring, while RAID 5 offers (N-1)/N capacity with single-drive fault tolerance.