I managed to find this, maybe you can get some ideas from here:
https://www.reddit.com/r/Bitcoin/comments/842ovw/running_bitcoin_nodes_behind_a_load_balancer/The most important thing is the node data folder.
I have setup a node that uses the data location a NAS with 4 disks in RAID 5. If one disk fails, I could still access the data normally until the bad disk is replaced. Doesn't affect at all your node.
You could expand that to 2 node machines that uses the NAS as storage so you can have full high availability.
I do not recommend using the same data folder for both nodes, it can be messy. Make a copy on the same NAS. In this way you can have also a backup.
You could have also a fifth disk with regular backup sync of that data folder, in case it gets corrupted or the whole nas is broken, you could just redirect your node to the backup disk and you are still in business. Any decent NAS have the option to sync regularly or periodically when you want a folder or entire LUN.
I still hope there will be some day an app for NAS that integrate a BTC node and/or LN.
