1. What is a RAID 6 Usable Space 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 available space after RAID 6 overhead.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \text{Usable} \) — Available storage space (TB)
• \( N \) — Total 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 usable space is the remaining drives multiplied by their size.

3. Importance of RAID 6 Capacity Calculation

Details: Proper capacity planning ensures you allocate enough drives to meet your storage needs while maintaining the fault tolerance benefits of RAID 6.

4. Using the Calculator

Tips: Enter the total 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 4 drives, though some implementations allow 3 drives.

Q3: How does drive size affect usable space?
A: Larger drives increase usable space proportionally, but also increase rebuild times if a drive fails.

Q4: Does this calculation include formatting overhead?
A: No, this shows raw capacity. Actual usable space will be slightly less due to filesystem overhead.

Q5: How does RAID 6 compare to other RAID levels?
A: RAID 6 offers better fault tolerance than RAID 5 (which uses only 1 parity drive) but less usable space than RAID 0 or RAID 10.