Linux

System Info — Know Your Linux System

Use Linux commands to quickly check OS version, kernel, CPU, memory, uptime, and hardware information.

March 25, 20255 min read

linuxsysadminsystem-infohardware

OS and Kernel Info

uname -a                    # All system info in one line
uname -r                    # Kernel version only
uname -m                    # Architecture (x86_64, arm64)
hostnamectl                 # Hostname, OS, kernel, architecture
cat /etc/os-release          # Distribution name and version
lsb_release -a              # Detailed distro info

CPU and Memory

lscpu                       # CPU model, cores, speed
cat /proc/cpuinfo           # Very detailed CPU info
nproc                       # Number of available CPU cores

free -h                     # RAM usage in human-readable form
cat /proc/meminfo           # Detailed memory info

Uptime and Load

uptime                      # System uptime and load averages
uptime -p                   # Pretty: "up 5 days, 3 hours"
who                         # Who is logged in right now
w                           # Users + what they're doing
last                        # Login history

Hardware Information

lspci                       # PCI devices (GPU, network cards)
lsusb                       # Connected USB devices
lsblk                       # Block devices (disks, partitions)
lshw -short                 # Hardware summary (needs sudo)
sudo dmidecode --type memory  # RAM slots and details

Install neofetch or fastfetch for a beautiful summary of all system info in one command: sudo apt install neofetch && neofetch.

Quick Check

Which command shows the kernel version?

Exercise

Find your CPU model and number of cores, then check how much RAM is available.