System information
Distro info
lsb_release -a
cat /etc/os-release
uname -a
# kernel version
uname -r
Who are you?
# who you are logged in as
whoami
linuxuser
# who is logged into the system
who
linuxuser tty1 2024-11-30 15:11
linuxuser pts/0 2024-11-30 15:11 (192.168.56.1)
# what logged in users are doing
w
17:04:00 up 3:32, 2 users, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
linuxuse tty1 - Sat15 25:52m 0.08s 0.03s -bash
linuxuse 192.168.20.10 Sat15 25:53m 0.00s 0.03s sshd: linuxuser [priv]
who’s IP address is this?
whois 192.168.56.1
#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2024, American Registry for Internet Numbers, Ltd.
#
NetRange: 192.168.0.0 - 192.168.255.255
CIDR: 192.168.0.0/16
NetName: PRIVATE-ADDRESS-CBLK-RFC1918-IANA-RESERVED
...
How long system running
uptime
04:02:12 up 45 min, 2 users, load average: 0.00, 0.00, 0.00
Hardware info
lscpu # CPU architecture
lsblk # block devices
lspci # PCI devices
lsusb # Attached USB devices
Memory and CPU usage
free
Parses the /proc/meminfo file and shows total available memory:
# shared - tmpfs to maintain pseudo fs like /sys and /dev
# buff/cache - kernel block I/O
free -h
total used free shared buff/cache available
Mem: 7.8Gi 631Mi 7.0Gi 3.8Mi 373Mi 7.1Gi
Swap: 0B 0B 0B
# available column is free memory without swapping (in Mi)
free -m
total used free shared buff/cache available
Mem: 7942 714 6593 3 925 7227
Swap: 0 0 0
vmstat
Checks swap usage. You can run it over an extended period of time. This gives you 4 readings at 30-second intervals:
# si - swapped into memory
# so - swapped out of memory
vmstat 30 4
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 0 4996868 1537492 18966428 0 0 18 61 23 1 4 2 95 0 0
0 0 0 5006424 1537504 18956112 0 0 0 61 6112 7490 4 4 92 0 0
Processes
top
htop
Disk usage
df
Displays disk usage by partition. Use the -i option to see the number of inodes left in the fs. ext3 and ext4 filesystems allocate a specific number of inodes, and you can’t make more files when you run out of inodes.
df -t <fstype> -i -h
# all disk partitions, human-readable
df -ih
Filesystem Inodes IUsed IFree IUse% Mounted on
tmpfs 3.9M 1.6K 3.9M 1% /run
/dev/nvme0n1p3 30M 1.7M 28M 6% /
tmpfs 3.9M 323 3.9M 1% /dev/shm
tmpfs 3.9M 6 3.9M 1% /run/lock
/dev/nvme0n1p1 0 0 0 - /boot/efi
tmpfs 793K 178 793K 1% /run/user/1001
# ext4 disk partitions
df -it ext4 -h
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/nvme0n1p3 30M 1.7M 28M 6% /
# tmpfs partitions
df -it tmpfs -h
Filesystem Inodes IUsed IFree IUse% Mounted on
tmpfs 3.9M 1.6K 3.9M 1% /run
tmpfs 3.9M 323 3.9M 1% /dev/shm
tmpfs 3.9M 6 3.9M 1% /run/lock
tmpfs 793K 178 793K 1% /run/user/1001
du
Displays disk usage by directory. Good for finding users or apps that take up the most disk space:
# -d - directory depth
du -d 1
12 ./assets
8 ./layouts
788 ./resources
6460 ./.git
1288 ./content
11012 ./node_modules
12 ./.github
8 ./themes
19700 .