df displays disk limits (size, used, avail) of mounted filesystems.
Typically, the most important mountpoints to consider are root (/) and boot (/boot)
Examples
Human-Readable Form (-h)
$ df -h
Filesystem Size Used Avail Use% Mounted on
dev 7.8G 0 7.8G 0% /dev
run 7.8G 1.3M 7.8G 1% /run
/dev/nvme0n1p3 457G 32G 402G 8% /
tmpfs 7.8G 22M 7.8G 1% /dev/shm
tmpfs 7.8G 1.2M 7.8G 1% /tmp
/dev/nvme0n1p1 511M 104M 408M 21% /boot
tmpfs 1.6G 12K 1.6G 1% /run/user/1000
- I
alias df='df -h'in my.zshrcto get the human-readable form by default.
Default Form
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
dev 8104460 0 8104460 0% /dev
run 8115748 1232 8114516 1% /run
/dev/nvme0n1p3 478232320 33257164 420608820 8% /
tmpfs 8115748 22396 8093352 1% /dev/shm
tmpfs 8115748 1192 8114556 1% /tmp
/dev/nvme0n1p1 523248 105996 417252 21% /boot
tmpfs 1623148 12 1623136 1% /run/user/1000