Server & Endpoint Monitoring

GridNMS can monitor Linux, macOS, and Windows machines the same way it monitors network devices: it connects over SSH with a dedicated, read-only account and reads CPU load, memory, disk usage, and uptime directly — no software to install on the machine being monitored.

This page covers setting up the read-only account on each operating system. Once the account exists, monitoring the machine works like monitoring any other device: add it under Devices, put it in the matching class (Linux Server, macOS, or Windows Server), and enter the account’s username and password.

Prefer not to create a local account?

If you’d rather install something small on the machine instead of exposing SSH, see the Log Forwarder — a lightweight agent built primarily for shipping logs, which also reports the same CPU/memory/disk metrics as a bonus. SSH monitoring stays the recommended default because it needs nothing installed on the endpoint at all.

How it works

GridNMS logs in with the read-only account on a schedule, runs a handful of built-in, harmless commands (reading memory/CPU stats, listing disk usage), and reads the results — the same way an administrator would type those commands by hand. Nothing is written back to the machine, and the account never needs administrator/root privileges for standard monitoring.

Linux

Linux hosts use the same built-in commands available on virtually every distribution (/proc, df), so no special software is required beyond an SSH server, which most Linux servers already run.

1. Create a dedicated, unprivileged user for monitoring, for example:

   sudo useradd -m -s /bin/bash gridnms-ro
   sudo passwd gridnms-ro

2. Make sure the account can log in over SSH (it can, by default, unless your SSH server restricts login to specific groups — if it does, add gridnms-ro to the allowed group).
3. In GridNMS, add the device under the Linux Server class and enter gridnms-ro and its password under that class’s SSH settings (or override it per device).

No sudo access is required — everything GridNMS reads is available to any logged-in user.

macOS

1. Create the account. Open System Settings → Users & Groups, click Add Account, and choose Standard (not Administrator). Give it a name like gridnms-ro and a strong password. A Standard account is sufficient — GridNMS never needs admin rights.
2. Turn on Remote Login. Open System Settings → General → Sharing, and enable Remote Login. Under “Allow access for,” choose Only these users and add the account you just created — this keeps the SSH door closed to every other account on the Mac.
3. Verify it works from another machine before wiring it into GridNMS:

   ssh gridnms-ro@<the-mac's-address>

   If you’re prompted for the password and land at a shell prompt, you’re done. If the connection is refused, double-check Remote Login is on and the account is in the allowed list.
4. In GridNMS, add the device under the macOS class and enter the account’s username and password under that class’s SSH settings (or override it per device).

Tip

On newer macOS versions, the first SSH command may prompt for a one-time Full Disk Access / Local Network permission in the Notification Center. Grant it — otherwise some commands can silently return empty results.

Windows (OpenSSH Server)

Windows monitoring currently requires the built-in OpenSSH Server feature to be enabled. Most Windows Server installs since Windows Server 2019 include it, but it isn’t turned on by default.

1. Enable OpenSSH Server, if it isn’t already:
   • Settings app: Settings → Apps → Optional Features → search for “OpenSSH Server” → Install.
   • Or PowerShell (as Administrator):

     Add-WindowsCapability -Online -Name OpenSSH.Server~~~~0.0.1.0
     Start-Service sshd
     Set-Service -Name sshd -StartupType Automatic

2. Create a dedicated, low-privilege local account:

   net user gridnms-ro <a-strong-password> /add

   Leave it in the default Users group — do not add it to Administrators. GridNMS only needs a plain, non-admin login.
3. Verify it works from another machine:

   ssh gridnms-ro@<the-server's-address>

   You should land at a C:\Users\gridnms-ro> prompt.
4. In GridNMS, add the device under the Windows Server class and enter the account’s username and password under that class’s SSH settings (or override it per device).

Windows support is newer

Windows SSH monitoring is our newest addition and is still being hardened against the variety of ways Windows can be configured to accept SSH connections. If a Windows device doesn’t pick up metrics after following the steps above, double check that OpenSSH Server is running (Get-Service sshd) and that Windows Firewall allows inbound connections on port 22, then reach out — we’re actively refining this path.

What gets monitored

Once connected, GridNMS reports:

• CPU load — recent load average (Linux/macOS) or CPU utilization percent (Windows)
• Memory — total and free RAM, plus swap on Linux/macOS
• Disk usage — percent used per mount point (Linux/macOS) or drive letter (Windows)
• Uptime (Linux/macOS)
• OS version — shown on the device’s overview

These appear on the device’s detail page the same way any other monitored metric does, and can be charted, thresholded, and alerted on like any other data point.