I have a 18.04.3 server set up running an OpenVPN server. This machine has fairly limited RAM since it is running on a virtual host with other servers. This machine is soley dedicated to VPN and is an important service for my work.
I noticed lots of snapd processes taking up much of the RAM. Is it safe to uninstall (or event just stop the processes) snapd to gain back this precious resource?
If you are not using snaps, then it is safe to uninstall snapd. Several OpenVPN implementations are in the Snap Store, so do be sure you are not using one of them.
snap list // List the snaps installed on your system
sudo apt remove snapd // Uninstall snapd
If you change your mind and wish to begin using snaps, then you must reinstall snapd.
sudo apt install snapd
A future release-upgrade may re-install snapd, and you might need to remove it again.
snapdis useful if and only if you want to install some app from snap: snapcraft.io/store In your case, I think you don't need it at all.