1
NAS 1 · ACTIVE
Istanbul
local
backup: Primary data source — pushes nightly restic to NAS 2 + NAS 3.
failure: Disk failure / hardware death → restore from NAS 2.
The 3-2-1 rule, exceeded: four copies, two media, two offsite.
4 copies · 2 media · 2 offsite · RPO ≤ 24h · RTO hours (local) / days (offsite)
NAS 1 is the only writer. Every night it pushes encrypted, deduplicated restic snapshots to the other three units. The copies never push back — restore happens on demand, one direction only.
Istanbul
Istanbul
Tallinn
Tallinn
A backup never restored is a hope — quarterly restore drills.