1. What is ZFS RAID Capacity?

ZFS RAID capacity refers to the usable storage space available in a ZFS pool after accounting for redundancy (mirroring or parity). The capacity depends on the RAID type and the sizes of the disks in the vdev.

2. How Does the Calculator Work?

The calculator uses the following formulas based on RAID type:

Explanation: For mirrors, capacity equals the smallest disk. For RAIDZ, capacity equals total space minus parity disks (1 for RAIDZ1, 2 for RAIDZ2, etc.).

3. Importance of RAID Configuration

Details: Choosing the right RAID type affects both capacity and data protection. Mirrors offer better performance but lower capacity, while RAIDZ offers more capacity with some performance trade-offs.

4. Using the Calculator

Tips: Enter disk sizes in GB separated by commas (e.g., "1000,2000,3000"). Select the RAID type you plan to use. All disk sizes must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RAIDZ and traditional RAID?
A: ZFS RAIDZ is more flexible with variable disk sizes and better data integrity through checksumming and self-healing.

Q2: Can I mix different disk sizes in a vdev?
A: Yes, but capacity will be limited by the smallest disk in the vdev for each allocation.

Q3: How much space does ZFS reserve for overhead?
A: ZFS typically reserves about 3.2% of each disk for metadata, not accounted for in this calculator.

Q4: What's the recommended number of disks per vdev?
A: For RAIDZ1: 3-9 disks, RAIDZ2: 6-10 disks, RAIDZ3: 8-12 disks for optimal performance.

Q5: Can I expand a vdev by adding disks?
A: No, you cannot add disks to an existing vdev. You can only add new vdevs to a pool.