1. What is RAID Capacity Calculation?

RAID (Redundant Array of Independent Disks) capacity calculation determines the usable storage space in a RAID array after accounting for redundancy. Different RAID levels use varying numbers of parity drives to provide data protection.

2. How Does the Calculator Work?

The calculator uses the RAID capacity formula:

Where:

• Number of Drives — Total physical drives in the array
• Parity Drives — Number of drives used for redundancy/parity
• Drive Capacity — Storage capacity of each individual drive

Explanation: This formula calculates the net usable storage after reserving space for data protection. Different RAID levels use different numbers of parity drives.

3. Importance of RAID Capacity Planning

Details: Proper RAID capacity planning is essential for storage design, ensuring you have adequate usable space while maintaining the desired level of data protection and redundancy.

4. Using the Calculator

Tips: Enter the total number of drives in your array, the capacity of each individual drive (in TB), and the number of parity drives used by your RAID configuration.

5. Frequently Asked Questions (FAQ)

Q1: How many parity drives do different RAID levels use?
A: RAID 1 uses 1 parity drive per mirror, RAID 5 uses 1 parity drive, RAID 6 uses 2 parity drives.

Q2: Does drive capacity affect RAID performance?
A: Larger drives may take longer to rebuild but don't directly affect normal operation performance.

Q3: Can I mix different drive capacities in a RAID array?
A: Yes, but the array will typically be limited to the smallest drive's capacity for each drive.

Q4: What is the difference between raw capacity and usable capacity?
A: Raw capacity is the total of all drives, while usable capacity subtracts space used for parity and redundancy.

Q5: How does RAID level choice affect capacity?
A: RAID 0 offers full capacity but no redundancy, while RAID 1, 5, 6, and 10 sacrifice some capacity for data protection.