Depends on how many nines of uptime you need, of course, and other such things.
(Obviously, there are reams of cases where this isn't sufficient)
Thankfully I had both onsite and offsite backups; but it took a couple of weeks to order the new equipment, install it and set everything up again.
Now I "devops" all the things and always have the ability to spin up all the services and restore from backups within minutes. This is the new standard in my opinion.
1. How would power conditioners and lightning arresters handle these sorts of situations?
2. Was this using VMWare fault tolerant VMs, just out of curiosity? (It continually live-migrates one VM to a hot spare over a 10G link so either can disappear and the VM continues to run.) Or was this a bespoke application architecture implementing effectively the same thing?