CheatPress

System info Host, CPU, memory

Version procps-ng 4.0.4, util-linux 2.41, coreutils 9.7 · source

System info, Postcard, light preview Light · Postcard 102 × 152 mm · PDF System info, Postcard, dark preview Dark · Postcard 102 × 152 mm · PDF System info, Postcard, ink saver preview Ink saver · Postcard 102 × 152 mm · PDF
System info, A5, light preview Light · A5 148 × 210 mm · PDF System info, A5, dark preview Dark · A5 148 × 210 mm · PDF System info, A5, ink saver preview Ink saver · A5 148 × 210 mm · PDF
System info, A4, light preview Light · A4 210 × 297 mm · PDF System info, A4, dark preview Dark · A4 210 × 297 mm · PDF System info, A4, ink saver preview Ink saver · A4 210 × 297 mm · PDF
System info, A4 landscape, light preview Light · A4 landscape 297 × 210 mm · PDF System info, A4 landscape, dark preview Dark · A4 landscape 297 × 210 mm · PDF System info, A4 landscape, ink saver preview Ink saver · A4 landscape 297 × 210 mm · PDF
System info, A3, light preview Light · A3 297 × 420 mm · PDF System info, A3, dark preview Dark · A3 297 × 420 mm · PDF System info, A3, ink saver preview Ink saver · A3 297 × 420 mm · PDF
System info, A3 landscape, light preview Light · A3 landscape 420 × 297 mm · PDF System info, A3 landscape, dark preview Dark · A3 landscape 420 × 297 mm · PDF System info, A3 landscape, ink saver preview Ink saver · A3 landscape 420 × 297 mm · PDF
System info, Letter, light preview Light · Letter 8.5 × 11 in · PDF System info, Letter, dark preview Dark · Letter 8.5 × 11 in · PDF System info, Letter, ink saver preview Ink saver · Letter 8.5 × 11 in · PDF
System info, Tabloid, light preview Light · Tabloid 11 × 17 in · PDF System info, Tabloid, dark preview Dark · Tabloid 11 × 17 in · PDF System info, Tabloid, ink saver preview Ink saver · Tabloid 11 × 17 in · PDF

Start here

uname -a
Kernel and machine
hostnamectl
Host, OS and kernel
uptime
Up time and load
free -h
Memory and swap
lscpu
CPU model and cores
nproc
Usable CPU count
dmesg -T --level=err,warn
Recent kernel problems
vmstat 1 5
Live CPU, memory, I/O

Concepts

  1. What is it? OS, kernel, host
  2. How busy? load, CPU, memory
  3. What hardware? CPU, PCI, USB
  4. What went wrong? kernel log

System and OS

uname -a
Kernel name, release, arch and host
uname -r
Kernel release only
uname -m
Machine architecture (x86_64, aarch64)
uname -srm
Pick fields: kernel, release, machine
hostnamectl
Hostname, OS, kernel, virtualization
hostname
Print the current hostname
hostnamectl --json=pretty
Same facts as JSON for scripts
sudo hostnamectl set-hostname <name>
Set the static hostname
cat /etc/os-release
Distro name and version (ID, VERSION_ID)
. /etc/os-release && echo $PRETTY_NAME
Read the distro name in a script
systemd-detect-virt
Say whether in a VM or container
cat /proc/version
Kernel build string and compiler

Uptime and load

uptime
Time up, users, load averages (1/5/15 min)
uptime -p
Uptime in words
uptime -s
Boot time as a timestamp
who -b
Last boot time
w
Who is logged in and what they run
journalctl --list-boots
Boots the journal remembers
cat /proc/loadavg
Load averages plus running tasks

Memory

free -h
Memory and swap, human-readable
free -h -s <sec>
Repeat every <sec> seconds
free -h -c <n>
Stop after <n> reports
free -m
Sizes in MiB
free -h -t
Add a RAM + swap total row
free -h -w
Split buff and cache columns
free -L
Whole report on one line
grep -E 'MemAvailable|SwapFree' /proc/meminfo
Read exact kernel counters
vmstat -s
Memory and event counters, one per line

CPU

lscpu
Model, sockets, cores, threads, caches
nproc
CPUs usable by this process
nproc --all
Installed CPUs, ignoring limits
lscpu -e
One row per logical CPU
lscpu -J
CPU facts as JSON
lscpu -C
Cache sizes per level
grep -m1 'model name' /proc/cpuinfo
Quick CPU model name

vmstat

vmstat <sec> <count>
Sample every <sec>, stop after <count>
vmstat 1
Sample every second until Ctrl+C
vmstat -w <sec>
Wide output for big numbers
vmstat -t <sec>
Add a timestamp column
vmstat -S M <sec>
Show sizes in MB
vmstat -d
Per-disk read and write totals
vmstat -a
Active and inactive memory
vmstat columns
Column Read it as
r / b Runnable / blocked tasks; r above nproc means CPU-bound
si / so Swap in / out; non-zero means memory pressure
bi / bo Blocks read / written on disks
us sy id wa CPU user, system, idle, I/O wait

Hardware

lspci
List PCI devices (GPU, NIC, controllers)
lspci -nnk
IDs and the kernel driver in use
lspci -v
Verbose details per device
lspci -s <slot>
Only one slot, e.g. 00:02.0
lspci -t
Bus tree
lsusb
List USB devices
lsusb -t
USB tree with drivers and speeds
lsusb -v -d <vid>:<pid>
Full descriptors of one device
lsblk
Disks and partitions as a tree

Kernel log (dmesg)

dmesg -T
Log with readable timestamps
dmesg --level=err,warn
Only errors and warnings
dmesg -w
Follow new messages live
dmesg -H
Human mode: pager, colour, relative time
dmesg | tail -n 30
Latest messages
dmesg -T | grep -i <word>
Search the log
dmesg -x
Show facility and level names
dmesg -W
Follow, new messages only
dmesg --since '<time>'
Messages after a point in time
dmesg -k
Kernel messages only
sudo dmesg -C
Clear the ring buffer

Users and sessions

whoami
Name of the current user
id
UID, GID and all groups
id <user>
Same for another user
id -nG
Group names only
id -u
Numeric UID, for scripts
who
Logged-in sessions
who -q
Names and count of users
who -u
Sessions with idle time and PID
users
Logged-in user names on one line
loginctl list-sessions
Sessions as systemd sees them

Recipes

Quick host report
uname -srmgrep PRETTY_NAME /etc/os-releaseuptime -pnprocfree -h | head -2
Is it CPU, memory or disk?
uptime            # load vs nprocvmstat 1 5        # r, si/so, wa columnsfree -h           # available memorydmesg -T --level=err,warn | tail
Why did it reboot?
journalctl --list-boots | tail -n 3uptime -ssudo journalctl -b -1 -e   # end of previous bootdmesg -T | grep -iE 'oom|panic'
Is the hardware seen?
lspci -nnk | grep -iA3 'vga\|net'lsusb -tdmesg -T | tail -n 20   # after plugging in