I use systemD to run node smoothly, maybe someone knows how to improve it or is it good too?
[Unit]
Description=CLAJ Server
After=network.target
[Service]
Type=simple
User=root
Group=root
WorkingDirectory=/root/claj
ExecStart=/usr/bin/java -Xms256M -Xmx256M -jar claj-server.jar 1111
Restart=always
RestartSec=5
[Install]
WantedBy=multi-user.target

mm why not but the name is a little bit too long, "MindCup Russia" is better no?
also why not using a service but a good practice is to avoid a much as possible to run a program as root. you can try to create a user just for that and place the server in a more appropriate folder, instead of the root homedir. or you can use docker if you want.
anyway @lapin-b what do you think about his service file, as you done the same thing?

yes, I know, the practice for the user is their own service, but there is nothing on this machine, and unfortunately I did not study linux well, logging into the same ssh with a key, as indicated by the hoster (from whom I rented a VDS)

let's do this, you tell me how to do it in linux os - I'll do it and run it, fortunately there are enough resources

XD you absolutely want to put contry+region. For moment the region is useless, you just need to name your server Node name+country.

And for your service you can create a new user by doing "adduser claj", and then change the root user into your service, by claj. also you can move the server to the opt folder by doing "mkdit /opt/claj; mv /root/claj-server.jar /opt/claj", and then change the working directory to that one. And to finish, set the permissions by doing "chow claj:claj -R /opt/claj".

This should work.

systemctl status claj.service

● claj.service - CLAJ Server
Loaded: loaded (/etc/systemd/system/claj.service; enabled; preset: enabled)
Active: active (running) since Thu 2026-06-25 12:51:49 UTC; 6s ago
Invocation: eb7d4a8353dd4746b1edb635f7423859
Main PID: 71821 (java)
Tasks: 20 (limit: 2315)
Memory: 41.8M (peak: 42.3M)
CPU: 484ms
CGroup: /system.slice/claj.service
└─71821 /usr/bin/java -Xms256M -Xmx256M -jar claj-server.jar 1111

Jun 25 12:51:49 joni systemd[1]: Started claj.service - CLAJ Server.
Jun 25 12:51:49 joni java[71821]: [25-06-2026 12:51:49] [I] Server loaded and hosted on port 1111. Type 'help' for help.

GNU nano 8.4 /etc/systemd/system/claj.service

[Unit]
Description=CLAJ Server
After=network.target
[Service]
Type=simple
User=claj
Group=claj
WorkingDirectory=/home/claj
ExecStart=/usr/bin/java -Xms256M -Xmx256M -jar claj-server.jar 1111
Restart=always
RestartSec=5
[Install]
WantedBy=multi-user.target

it is usually customary to specify the region in Russia, because it happens that in the east (Kamchatka/border with China) the US ping is less than in Russia itself on the border of Finland (west / St. Petersburg)

is it possible to run it somehow but with access to the console? but not through tmux/screen solutions?

@lapin-b can you help about that? you done the same thing.