1. What is a RAID 5 Capacity Calculator?

Definition: This calculator estimates the usable storage capacity 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 arrays by determining the actual usable space in a RAID 5 configuration.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \text{Capacity} \) — Usable storage capacity (TB)
• \( N \) — Number of drives in the array
• \( \text{DriveSize} \) — Size of each individual drive (TB)

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

3. Importance of RAID 5 Capacity Calculation

Details: Proper capacity planning 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.

Q2: Does this account for formatting overhead?
A: No, this calculates raw capacity. Actual usable space will be slightly less due to filesystem overhead.

Q3: What's the maximum number of drives in RAID 5?
A: While technically unlimited, practical limits are usually around 16 drives due to rebuild times and failure risks.

Q4: How does drive size affect performance?
A: Larger drives take longer to rebuild if one fails, increasing vulnerability during rebuild.

Q5: Can I mix different drive sizes?
A: Yes, but the array will use the smallest drive's size for all capacity calculations.