1. What is a RAID 5 Drive Size Calculator?

Definition: This calculator determines the required size for each drive in a RAID 5 array based on the desired total capacity and number of drives.

Purpose: It helps IT professionals and system administrators properly configure RAID 5 storage arrays.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \text{DriveSize} \) — Size required for each drive (TB)
• \( \text{Capacity} \) — Desired usable storage capacity (TB)
• \( N \) — Total number of drives in the array

Explanation: RAID 5 uses one drive's worth of space for parity, so the total usable capacity is (N-1) × drive size.

3. Importance of RAID 5 Drive Size Calculation

Details: Proper calculation ensures you purchase drives of the correct size to achieve your desired storage capacity while maintaining fault tolerance.

4. Using the Calculator

Tips: Enter the desired usable capacity in TB and the number of drives (minimum 3). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is N-1 used in the formula?
A: RAID 5 dedicates one drive's worth of space for parity information, leaving N-1 drives worth of space for actual data.

Q2: What's the minimum number of drives for RAID 5?
A: RAID 5 requires a minimum of 3 drives to function properly.

Q3: Does this account for drive formatting overhead?
A: No, this calculates raw capacity. Actual usable space will be slightly less due to filesystem overhead.

Q4: Can I use different sized drives?
A: Technically yes, but RAID 5 will only use the smallest drive's capacity across all drives for parity.

Q5: How does this compare to RAID 6?
A: RAID 6 uses two drives for parity (N-2), providing better fault tolerance but less usable space.