FAQ
Short answers to the questions people ask most about 3R Monitor, with links to the details.
If something doesn't work, start with Troubleshooting: it lists the messages you may see and what to do about each one.
About 3R Monitor
Is it really free?
Yes. 3R Monitor is freeware: free for personal and commercial use, on as many servers as you own or operate. You may not sell it or pass the package on to others: they should download it from 3rsoft.com.pa. See License.
Does it send my data to 3R Soft?
No. Everything stays on your master. The master only asks 3rsoft.com.pa for new versions (sending the installed version, the operating system and the architecture), and you can turn that off. See Security and privacy.
Which systems does it run on?
Linux with systemd, on x86_64, arm64, armv7 or 386: Ubuntu, Debian, AlmaLinux, Rocky Linux, RHEL, CentOS Stream and others. There is no agent for Windows or macOS. Websites, ports and DNS records of any other system can still be checked from the master with monitors. See Requirements.
Can I watch a server without installing anything on it?
Partly. A monitor checks a website, an API, a TCP port, Ping, a certificate or a DNS record from the master. CPU, memory, disks, services, software, vulnerabilities and traffic need the agent.
How much does the agent use?
Little: about 58 MB of network traffic a day with the default 3-second report interval, and a single program with no dependencies. A longer interval uses less. See Bandwidth usage.
Does the agent open a port on my servers?
No. Agents only connect out to the master, over HTTP(S), and don't need to be reachable. Only the master needs one open port (8899 by default). See Requirements.
Can I get alerts other than by email?
Alerts are sent by email, through your own SMTP server. The panel also shows them live, and a display screen can show the status on a TV. See Alerts and email.
Do I need the AI?
No. AI analysis is off until you add a model of your own, and everything else works without it. If you use it, names and IPs are sent to the model as codes, and you choose what it may do on your servers. See AI analysis and AI on-call.
Installing
Which server should be the master?
Any Linux server that your other servers can reach. Preferably one that doesn't go down together with your most important services, for example a small server at another provider: if the master is down, nothing is left to send the alert. Install it as master + agent, so it is monitored too. See Install the master.
How do I add many servers at once?
Use the enrollment key: one command for every server, and each server registers itself. It also works from SSH loops, cloud-init and Ansible. See Install the agents and Many servers from a script or a tool.
Can I install without running a script from the internet?
Yes. Download the installer and read it first, install from the release package, or install everything by hand. See Manual installation.
Is HTTPS required?
Not on a private network. On the internet, use it: without it, passwords travel unencrypted, and passkeys don't work. The installer can get a free certificate for a domain. See HTTPS.
Day to day
How do I add another person?
Users → ＋ Add user. Every account can change everything; for someone who only needs to look, create a share link instead. See Users.
How do I stop alerts during maintenance?
Turn Enable alerts off in the server's settings (Servers → Settings), and on again afterwards. The server keeps its history. For a monitor, pause it. See Server settings.
Why does an alert arrive a few minutes late?
Alerts are combined on purpose: the first email waits 1 minute, then at most one every 5 minutes. You can change it. See Alert emails arrive late.
How long is history kept?
Charts and check results 30 days (you can change it), traffic usage 13 months, incidents a year. See How long data is kept.
Why does the traffic usage differ from my provider's bill?
3R Monitor counts the bytes on the server's network interfaces. Providers may count other traffic, only the public interface, or 1000³ bytes per GB instead of 1024³. Choose the interface and how the quota counts in Servers → Settings → Traffic usage. See Traffic usage.
How do I update?
Click Update now in System → Software updates, then Install. Agents update themselves to the master's version. See Upgrade and uninstall.
Changes
How do I change the panel's address or port?
The port is listen in /etc/3rmonitor/master.conf (restart the master afterwards); the address the agents and emails use is Settings → General → Panel public URL. Agents that are already installed keep their old address: with a domain, just point the DNS record to the master; otherwise run sudo 3rmonitor bind --master NEW_URL --token TOKEN on each agent. See Configuration files and Re-enroll an agent.
How do I move the master to another server?
Back up /var/lib/3rmonitor and /etc/3rmonitor, install the master on the new server, restore the backup, and point the agents to the new address. See Restore, or move the master to a new server.
I reinstalled a server. How do I keep its history?
Run that server's install command again, from Servers → ⋯ → Install command. It carries the same token, so the server keeps its name, settings and history. If the agent is already installed, use Agent already installed? Just re-enroll it as this server in the same window. See Re-enroll an agent.
How do I remove a server?
Delete it in Servers (⋯ → Delete), then uninstall the agent on it with sudo bash /opt/3rmonitor/install.sh uninstall. See Remove a server.
Help
Where do I get help?
- Troubleshooting explains the messages you may see and what to do.
- System → Help and support in the panel links to this documentation and to info@3rsoft.com.pa for problems and bugs. See Getting help for what to include, so we can answer on the first email.
- Security problems: privately to security@3rsoft.com.pa. See Reporting a security problem.