You will have to update the server whenever a patch is released on Steam.

If the server is running, stop it by pressing Ctrl + C in the terminal (or screen/tmux instance) that the server is attached to. Otherwise, switch to the steam user.

sudo -u steam -i

Launch SteamCMD

cd /home/steam/steamcmd
./steamcmd.sh

Login to the Steam account used when installing the server.

login myusername

Set the Arma 3 installation directory used when installing the server.

force_install_dir ./arma3/

Update the Arma 3 Linux server. The validate option will check for corruption.

app_update 233780 validate

Exit SteamCMD.

exit