Show filesystem info

Show ext2/3/4 metadata: block size, mount count, last mount time

tune2fs -l /dev/sda1 | grep -E 'Block (count|size)|Mount count|Last mount'

More linux commands

Disk usage with depth

du -h --max-depth=2 /var | sort -rh | head -20

Disk usage of /var up to 2 directory levels deep
Free disk space summary

df -hT --type=ext4 --type=xfs --type=btrfs

Show free space only for real filesystems (skip tmpfs/overlay)
Interactive partition editor

fdisk /dev/sdb

Interactive MBR/GPT partition table editor
Partition with parted (GPT)

parted /dev/sdb -- mklabel gpt mkpart primary ext4 1MiB 100%

Create a single GPT partition using the full disk
Show LVM physical volumes

pvs && pvdisplay

List LVM physical volumes with space usage