Backups and upgrades

Identity is state, not disposable cache.

Component	Preserve
Sidecar/service	/data, especially service identity
Relay/node	node identity and configuration
Beacon relay	persistent relay identity/data
Agent	/data after enrollment
Control	/data for inventory and registrations
Client	profile/identity; CA if the same local trust root must be kept

Rolling upgrades

Upgrade one backbone node, verify health/rejoin and run an external .knot check before updating the next.

Sidecars can normally be pulled/restarted while keeping the same persistent volume, preserving the service address.

Source