Linux Basics: Checking System Information
Before troubleshooting a Linux machine, check which distribution and kernel it is running. These read-only commands work on Debian and Ubuntu and do not require sudo.
Identify the distribution
cat /etc/os-releaseThis file describes the installed operating system. Look for PRETTY_NAME for a readable name and VERSION_ID for the release number. These identify the distribution, not the Linux kernel version.
Use the release information when choosing installation instructions. A guide for a different release may reference packages or settings that do not match your system.
Check the kernel and architecture
uname -r
uname -muname -r prints the running kernel release. uname -m prints the machine architecture reported by the kernel, such as x86_64 or aarch64.
In a container, the distribution can differ from the host’s, while the kernel is shared with the host. Keep that distinction in mind when comparing these results.
Look at memory and uptime
free -h
uptimefree -h displays memory and swap figures with readable units. For a quick estimate of room for more applications, look at the available column. A small free value alone does not mean memory is exhausted, because Linux also uses memory for caches.
uptime shows how long the system has been running and its load averages over one, five, and fifteen minutes. Load averages are not CPU-usage percentages.
Inside containers, memory and uptime figures may describe the host rather than the container’s limits. Treat them as context, not a complete resource diagnosis.
Reference
Acknowledgements
This post was created with assistance from AI.
Linux Basics — lesson 16 of 25. Series index
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