1. What is Synology RAID Capacity Calculation?

The Synology RAID capacity calculation determines the usable storage space in a RAID array, accounting for parity disks that provide redundancy but reduce available capacity.

2. How Does the Calculator Work?

The calculator uses the RAID capacity formula:

Where:

• \( total\_disks \) — Total number of disks in the array
• \( min\_size \) — Size of the smallest disk in the array (GB)
• \( parity\_disks \) — Number of disks used for parity/redundancy

Explanation: The formula calculates effective storage by multiplying total disks by smallest disk size (RAID limitation), then reducing by the proportion used for parity.

3. Importance of RAID Capacity Planning

Details: Proper capacity planning ensures you have enough usable storage while maintaining appropriate redundancy levels for your data protection needs.

4. Using the Calculator

Tips: Enter total number of disks, size of smallest disk (in GB), and number of parity disks. All values must be valid (total disks > 0, min size > 0, parity disks ≥ 0).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RAID types?
A: RAID types (5, 6, SHR, etc.) differ in parity disk requirements - RAID5 uses 1 parity disk, RAID6 uses 2, etc.

Q2: Why use smallest disk size?
A: In most RAID configurations, all disks are limited to the size of the smallest disk in the array.

Q3: What's typical parity configuration?
A: RAID5 uses 1 parity disk, RAID6 uses 2. Synology Hybrid RAID (SHR) may use 1 or 2 depending on configuration.

Q4: How does this apply to SHR?
A: For Synology Hybrid RAID, the calculation works similarly but may have more complex optimization with mixed disk sizes.

Q5: What about RAID1?
A: RAID1 is simple mirroring - usable capacity is exactly half the total raw capacity (or equal to one disk's capacity).