How to see used and free disk space
Use the df command to see disk space usage. By default, the output will show 1K-blocks. To see sizes in a human-readable format, use the --human-readable option.
Show all file systems and their disk usage
By specifying the --all option, we see all mounted file systems, even though they don’t have disk usage information.
# df --all --human-readable
Filesystem Size Used Avail Use% Mounted on
sysfs 0 0 0 - /sys
proc 0 0 0 - /proc
udev 1.9G 0 1.9G 0% /dev
devpts 0 0 0 - /dev/pts
tmpfs 392M 1.1M 391M 1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv 14G 6.9G 6.4G 53% /
securityfs 0 0 0 - /sys/kernel/security
tmpfs 2.0G 12K 2.0G 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
cgroup2 0 0 0 - /sys/fs/cgroup
pstore 0 0 0 - /sys/fs/pstore
bpf 0 0 0 - /sys/fs/bpf
systemd-1 - - - - /proc/sys/fs/binfmt_misc
hugetlbfs 0 0 0 - /dev/hugepages
mqueue 0 0 0 - /dev/mqueue
debugfs 0 0 0 - /sys/kernel/debug
tracefs 0 0 0 - /sys/kernel/tracing
configfs 0 0 0 - /sys/kernel/config
none 0 0 0 - /run/credentials/systemd-sysusers.service
fusectl 0 0 0 - /sys/fs/fuse/connections
systemd-1 - - - - /mnt/projects
/dev/loop2 39M 39M 0 100% /snap/snapd/21465
/dev/loop0 88M 88M 0 100% /snap/lxd/28373
/dev/loop4 88M 88M 0 100% /snap/lxd/27948
/dev/loop5 64M 64M 0 100% /snap/core20/2264
/dev/sda2 1.7G 253M 1.4G 16% /boot
binfmt_misc 0 0 0 - /proc/sys/fs/binfmt_misc
sunrpc 0 0 0 - /run/rpc_pipefs
tmpfs 392M 1.1M 391M 1% /run/snapd/ns
nsfs 0 0 0 - /run/snapd/ns/lxd.mnt
tmpfs 392M 4.0K 392M 1% /run/user/1000
/dev/loop6 64M 64M 0 100% /snap/core20/2318
/dev/loop3 39M 39M 0 100% /snap/snapd/21759
192.168.1.10:/Projects 10G 2.8G 7.3G 28% /mnt/projects
To shorten this command, combine the options and use df -ah.