TrueNAS

TrueNAS turns a PC full of hard drives into a rock-solid network storage appliance. Its defining feature is ZFS, a filesystem obsessed with data integrity: every block is checksummed, silent corruption (bit rot) is detected and automatically repaired, and snapshots let you roll back to any point in time almost instantly. For irreplaceable data like family photos, that peace of mind is the whole point.

There are two editions. TrueNAS SCALE is Linux-based and the modern default — it runs Docker apps and virtual machines alongside storage, so your NAS can also host services. TrueNAS CORE is the older FreeBSD-based line. Both share the same excellent ZFS foundation and a mature web interface for managing pools, datasets, shares and permissions.

Plan your hardware around ZFS: it loves RAM (roughly 1 GB per TB is a comfortable baseline), and while ECC memory is recommended for maximum safety, it is not strictly required. Use an HBA in IT mode rather than a RAID card so ZFS can see the disks directly. Remember that RAID-Z protects against drive failure but is not a backup — you still need snapshots replicated elsewhere and an offsite copy to be truly safe.