I currently have a two node cluster (node 1 and 3) and each node has two ssd's attached (node 1 has a mini pcie sata adapter). I was getting ready to install longhorn as the file system when I realized that I misread the instructions as it seems longhorn needs three nodes. Does anyone have any suggestions for a file system (besides NFS) that works with a two node cluster? Ideally I'll add two more nodes but with availability and prices being what they are I'm probably stuck with the two nodes I've got.

Longhorn definitely isn't ideal for a 2 node cluster, but you could still use it for now. By default though, any volumes will have 3 replicas and you'll want to set them to 1 or 2 replicas instead.

That's good to know, thanks!