I always find it funny when someone on the Internet says “ZFS is memory hungry” or “ZFS needs at least 8 GB of ECC RAM to run”. Nonsense.
To prove it, I installed #FreeBSD 15.1 (64 bit!) on a 23 year old PC, with ZFS and only 1 GB of RAM, running multiple jails without issue. 😎
It has been a bit tricky to get FreeBSD 15.1 to boot off a modern SATA drive, but I found some old PCI SATA controller I bought way back in the Windows 7 days which is still supported.
The single core AMD Athlon 64 3000+ is a bit slow, but pkgbase really helps with speeding up installing patches. It’s still fast enough to reach 604 Mbit/s in iperf3 (and 490 Mbit/s in client mode).
If I wanted to, I could even turn this ancient machine into a NAS, which really proves that old PCs aren’t trash, but modern software is.