How to kick all players in GMod
Type kickall Server restarting for an update in the server console to kick every connected player with that message.
kickall
Kicks every connected player, with an optional message.
kickall [message] Examples
kickall Server restarting for an update Clear the server with a reason.
Arguments
messageOptional- Message shown to players.
What it does
Useful before maintenance or a restart.
The game's own description: Kicks everybody connected with a message.
Run it on your server
On a SLASHPLAY server, type it in the Console tab of the server page; the reply shows right under it. A value set there lasts until the server restarts. To keep it, add the line to garrysmod/cfg/server.cfg. New to this? Start a GMod server first.
Your own
GMod server.
From $0.03 an hour, only while it runs. New accounts get 6 free tokens.