A crucial website ought to have:
- a primary server: Ryzen CPU, NVMe storage.
- a secondary standby: Xeon CPU, SSD storage.
- a third replica: Atom CPU, spinning rust storage.
- a fourth backup: ARMv5 CPU, VHS tape.
- a system to automatically perform failover.
- a cat to look over this system.
- a robot to feed the cat.
- an engineer to repair the robot.
These can get your data 99.99% secure.
Now add some cold storage:
- punch cards kept in California.
- microfilm buried in Antarctica.
- vinyl record launched to Jupiter.
If all four online servers are lost, you are looking at a lengthy downtime, but your data would be 99.9999% secure by recovering from the cold storage.
To finally reach 100%, transmit your data as radio waves toward a black hole.
If California fells into the ocean, Antarctica melts, and the sun explores taking out Jupiter, you can travel to the black hole and access your data.
According to physics, information cannot be destroyed by a black hole.
It's the ultimate storage with infinite space.
Once you enter the black hole, you won't be able to come back, but you are with your data forever.