Check available disk space on your server with SSH for Linux Print

After connecting to your Linux server via SSH, you have several commands available to check disk space usage, both at the filesystem level and for individual directories and files. This guide covers the most useful ones.

On shared or reseller hosting? You can check your disk usage without SSH by logging in to cPanel and going to Files → Disk Usage. The commands in this guide are for VPS and dedicated server customers with SSH access.

Checking overall disk space, df

The df command (disk free) shows disk space usage for each mounted filesystem on the server.

Human-readable output (recommended)

df -h

The -h flag formats sizes in human-readable units (GB, MB) rather than raw bytes. Example output:

Filesystem      Size  Used Avail Use%  Mounted on
/dev/sda1        50G   18G   30G  38%  /
tmpfs           2.0G     0  2.0G   0%  /dev/shm
/dev/sda2       200G  145G   45G  73%  /home

The key columns to read:

Show disk usage in kilobytes

df -k

Show only a specific directory's filesystem

df -h /home

Check inode usage

Inodes represent the number of files and directories. A server can run out of inodes even if there is still disk space available, causing errors when creating new files:

df -i

If the IUse% column is near 100%, you have too many files. See the section on finding and clearing large numbers of files below.

Finding what is using space, du

The du command (disk usage) shows how much space individual directories and files are consuming. This is how you find out what is filling up your disk.

Check total size of a specific directory

du -sh /home/username

The -s flag gives a summary total rather than listing every subdirectory, and -h makes it human-readable.

List the largest subdirectories inside a directory

du -h --max-depth=1 /home/username | sort -rh

This shows the size of each immediate subdirectory inside /home/username, sorted largest first. Useful for quickly identifying which subfolder is consuming the most space.

Find the top 10 largest directories on the whole server

du -h / --max-depth=3 2>/dev/null | sort -rh | head -10

Find the largest individual files in a directory

find /home/username -type f -printf '%s %p\n' | sort -rn | head -20

This lists the 20 largest files under /home/username, sorted by size in bytes. Useful for tracking down large log files, database dumps, or backup archives left on the server.

Find files larger than a specific size

find /home/username -type f -size +100M

This finds all files over 100MB. Change 100M to any size you want to filter by (e.g. 500M for 500MB, 1G for 1GB).

Common causes of disk space issues on Linux servers

If your disk is filling up unexpectedly, check these common culprits first:

Monitoring disk space over time

To watch disk space change in real time (useful during a file transfer or cleanup):

watch -n 5 df -h

This refreshes the df -h output every 5 seconds. Press Ctrl+C to exit.

Quick reference