NFS is really good inside a LAN, just use 4.x (preferably 4.2) which is quite a bit better than 2.x/3.x. It makes file sharing super easy, does good caching and efficient sync. I use it for almost all of my Docker and Kubernetes clusters to allow files to be hosted on a NAS and sync the files among the cluster. NFS is great at keeping servers on a LAN or tight WAN in sync in near real time.

What it isn’t is a backup system or a periodic sync application and it’s often when people try to use it that way that they get frustrated. It isn’t going to be as efficient in the cloud if the servers are widely spaced across the internet. Sync things to a central location like a NAS with NFS and then backups or syncs across wider WANs and the internet should be done with other tech that is better with periodic, larger, slower transactions for applications that can tolerate being out of sync for short periods.

The only real problem I often see in the real world is Windows and Samba (sometimes referred to as CIFS) shares trying to sync the same files as NFS shares because Windows doesn’t support NFS out of the box and so file locking doesn’t work properly. Samba/CIFS has some advantages like user authentication tied to active directory out of the box as well as working out of the box on Windows (although older windows doesn’t support versions of Samba that are secure), so if I need to give a user access to log into a share from within a LAN (or over VPN) from any device to manually pull files, I use that instead. But for my own machines I just set up NFS clients to sync.

One caveat is if you’re using this for workstations or other devices that frequently reboot and/or need to be used offline from the LAN. Either don’t mount the shares on boot, or take the time to set it up properly. By default I see a lot of people get frustrated that it takes a long time to boot because the mount is set as a prerequisite for completing the boot with the way some guides tell you to set it up. It’s not an NFS issue; it’s more of a grub and systemd (or most equivalents) being a pain to configure properly and boot systems making the default assumption that a mount that’s configured on boot is necessary for the boot to complete.