How to host an Arma 3 server: server.cfg, missions, mods and signature keys

Arma 3 servers are less about quick matches and more about running something: a milsim unit’s weekly operation, a persistent Altis Life or King of the Hill community, an Antistasi campaign with friends, or a server for testing your own missions. That gives Arma a reputation as a complicated game to host, but the parts are logical once you see them laid out: two config files, a missions folder, your mods, and their signature keys. This guide explains each, covers what drives performance, and shows how we set a server up for you on GGHOST Cloud.

How an Arma 3 dedicated server works

The Arma 3 dedicated server runs the mission for everyone: the scripts, the AI, vehicles, physics and every player’s state. Missions are where the real work happens. A mission is a packed .pbo file in the server’s mpmissions folder, and it decides what the server spends its time on. The same server can be nearly idle on a small PvP mission and fully loaded on a large co-op operation with hundreds of AI.

The server is started with a set of launch parameters, the important ones being:

• -config= pointing to your server.cfg.
• -cfg= pointing to your basic.cfg.
• -mod= and -serverMod= listing the mods to load.
• -profiles= for where logs and profile data are written.

What drives CPU and memory use

We do not publish a fixed sizing table for Arma 3, because the mission and mods matter far more than the player count. In plain terms:

• AI count is usually the biggest load. Arma’s AI is detailed, and lots of active AI units keep the CPU busy.
• Scripts. Heavily scripted missions and frameworks add steady CPU load.
• Mods. Large mod sets add memory use and loading time.
• Players and vehicles add load on top, especially in busy areas of the map.

A fast CPU core matters for Arma. If your missions run large numbers of AI, a headless client (below) moves that work off the main server. Tell us your mission, mods and player count, and we size it with you. You pay for memory, not player slots.

Server config essentials

server.cfg

The main file for your server’s identity and rules:

• hostname: the name in the server browser.
• password: to make the server private.
• passwordAdmin: the admin password. Admins log in from in-game chat with #login.
• maxPlayers: the player limit.
• verifySignatures: set to 2 to accept only addons signed with keys the server knows (see below).
• BattlEye: enables BattlEye anti-cheat.
• A class Missions block if you want the server to start a specific mission automatically.

basic.cfg

basic.cfg holds network tuning settings. Arma’s defaults are a reasonable place to start. Change these only if you have a specific problem to solve, one setting at a time.

Missions

Upload mission .pbo files to mpmissions. Admins can switch missions in-game with #missions, or you can set a fixed mission in the class Missions block so the server loads it on startup.

Test new missions with a small group before your main session. A mission that fails to load, or a script error that floods the log, is much easier to fix with three people than with forty waiting.

Mods and signature keys

Arma 3’s mods are folders, usually named with an @, such as @CBA_A3. They are loaded in two ways:

• -mod= for mods players must also have. These are announced to clients when they join.
• -serverMod= for server-only mods, which are not sent to clients.

Both take a semicolon-separated list. On a Linux server, keep mod folder and file names lowercase, because the file system is case-sensitive.

Signature keys

Each signed mod ships a .bikey file. Copy it into the server’s top-level keys folder. With verifySignatures = 2, the server only accepts addons signed with a key it holds, which stops players joining with modified or mismatched files. A mod with no key can only be used as a server-side mod.

Headless clients

A headless client is an extra copy of the game connected to your server with no player behind it. Missions that support it hand their AI to the headless client, so the main server has less to simulate. Headless clients count towards maxPlayers, and the mission has to support offloading AI for it to help. For large AI-heavy co-op missions, it is the most effective performance change you can make.

Performance and fair-play tips

• Pick the region closest to your players. Our live regions today are Singapore and Europe (France–Germany border), with the United States (East, Central and West), the United Kingdom, India, Japan and Australia on demand.
• Restart between sessions. Long-running Arma servers build up state. Schedule a restart in the panel at a quiet time, or before each operation.
• Keep verifySignatures = 2 and BattlEye on for public servers.
• Keep the admin password private and give helpers their own panel sub-user rather than sharing your login.
• Watch the logs. Script errors in the server log often explain a slowdown long before players notice it.

Adding mods safely

Upload mods over SFTP, where large mod sets are much faster than the browser file manager. After each change, restart and read the log. Two rules:

• Match versions with your players. Most “kicked on join” problems are a mod version or key mismatch.
• Back up first. Take a backup from the panel before updating a mod set or changing frameworks, so you can roll back.

Backups

On GGHOST Cloud, backups run on a schedule you set and restore from the panel without opening a ticket. Your configs, missions, keys and any persistent mission data are worth protecting. If your mission saves to a database, the panel’s database access sits alongside the server. A daily backup, plus a manual one before every mod update, is a good routine.

Getting an Arma 3 server on GGHOST Cloud

Arma 3 is set up on request rather than through instant checkout:

1. Tell us what you need. Ask us on Discord (or open a ticket) with the game mode or mission, mods and player count you need.
2. We size it and quote. We work out the memory and CPU headroom for that setup and quote a monthly price. No setup fee, no contract; billing runs through app.gghost.cloud.
3. We set it up on our Pterodactyl panel, usually within a few days.
4. Upload and share the address. Add your missions, mods and keys, start the server, and give players the address and port shown in the panel.

You then have the full panel at panel.gghost.cloud: live console, file manager, SFTP, scheduled tasks, sub-users and database access. You can change startup flags, including your mod list, from the panel and restart. Every node is behind DDoS protection from our network providers, and support comes from the people who run the servers, on Discord or at hello@gghost.cloud.

The short version

Set your rules in server.cfg, leave basic.cfg at sensible defaults, put missions in mpmissions, load mods with -mod and -serverMod, and copy every .bikey into keys with verifySignatures = 2. Use a headless client for AI-heavy missions, back up before mod updates, and ask us on Discord when you want a server set up.