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 capacity after RAID 6 overhead.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \text{UsableSpace} \) — Available storage capacity (TB)
• \( N \) — Total number of drives in the array
• \( \text{DriveSize} \) — Capacity of each individual drive (TB)

Explanation: RAID 6 uses two drives worth of capacity for parity data, so the usable space is always the total of all drives minus two drives.

3. Importance of RAID 6 Capacity Calculation

Details: Proper capacity planning ensures you allocate sufficient storage for your needs while maintaining RAID 6's dual-parity fault tolerance.

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 stores parity information on two drives to maintain data integrity even if two drives fail simultaneously.

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 better efficiency.

Q3: Does this account for filesystem overhead?
A: No, this calculates raw storage capacity. Filesystems typically consume 2-5% additional space.

Q4: Can I mix different drive sizes?
A: Technically yes, but the calculator assumes identical drive sizes. With mixed sizes, the array will use the smallest drive's capacity for all.

Q5: How does this compare to RAID 5?
A: RAID 5 only uses one drive for parity, so its formula would be (N-1)×DriveSize, but offers less fault tolerance.