Code
linux
# Filesystem usage
df -h
df -hT
df -i # inode usage
# Directory sizes (human-readable, summarized)
du -sh /var/*
du -h --max-depth=1 /var | sort -h | tail -20
# Largest files
find / -type f -size +500M -exec ls -lh {} + 2>/dev/null
# Inodes per directory (find inode-hogging dirs)
for d in /*; do echo "$(find "$d" -xdev | wc -l) $d"; done | sort -n | tail
# Mount and unmount
mount /dev/sdb1 /mnt/data
umount /mnt/data
# LVM quick check
lvs && vgs && pvs