1. What is a RAID 6 Size Calculator?

Definition: This calculator estimates the usable storage capacity in a RAID 6 array based on the number of drives and their individual size.

Purpose: It helps IT professionals and system administrators plan storage arrays by determining the actual usable capacity after RAID 6 overhead.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: RAID 6 uses two drives worth of capacity for parity data, so the usable capacity is always the total of (number of drives minus 2) multiplied by the drive size.

3. Importance of RAID 6 Capacity Calculation

Details: Accurate capacity planning ensures proper storage provisioning, cost estimation, and performance expectations for RAID 6 arrays.

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 6 need two drives worth of capacity?
A: RAID 6 uses double parity, allowing the array to withstand the failure of any two drives without data loss.

Q2: What's the minimum number of drives for RAID 6?
A: RAID 6 requires a minimum of 3 drives, though 4+ is recommended for practical use.

Q3: How does this compare to RAID 5?
A: RAID 5 uses only one drive for parity (N-1), while RAID 6 uses two (N-2) for better fault tolerance.

Q4: Should I use the drive's raw or formatted capacity?
A: Use the raw TB capacity before formatting for most accurate calculations.

Q5: Does this account for filesystem overhead?
A: No, this calculates raw storage capacity. Actual usable space will be slightly less due to filesystem structures.