ZFS RAID Calculator
ZFS vdev math is different from traditional hardware RAID — work out usable capacity and fault tolerance for mirrors and RAIDZ1/2/3, including pools built from multiple striped vdevs.
Raw capacity
Usable capacity
Storage efficiency
Fault tolerance
Practical usable (80% full)
ZFS performance degrades as a pool fills up, since copy-on-write
needs contiguous free space to write efficiently — keeping usage
under roughly 80% is a common operational guideline, which is why
"practical usable" above is lower than raw usable capacity.
Fill in the form and press Calculate.