Linux · Storage & Backup

Check disk usage, manage partitions, and mount drives

Disk and partition management on Linux can be done entirely from the command line or through a graphical tool like GNOME Disks or KDE Partition Manager — both talk to the same underlying tools (`fdisk`, `parted`, `mkfs`), so it's fine to mix and match.

How to open Storage & Disk Management

  1. Run `lsblk` to confirm the partition shows the expected mountpoint.
  2. Run `df -h` and check the filesystem appears with the expected available space.
  3. If you edited `/etc/fstab`, run `sudo mount -a` to test it without rebooting — errors here mean fixing it now instead of at next boot.

What you should know

  • Check free space: `df -h` for mounted filesystems, `du -sh <folder>` to see what's taking up space in a specific directory.
  • List all drives and partitions: `lsblk` (tree view) or `sudo fdisk -l` (detailed).
  • Graphical partitioning: GNOME Disks (`gnome-disk-utility`, preinstalled on most GNOME systems) or GParted (`sudo apt install gparted` / `sudo dnf install gparted` / `sudo pacman -S gparted`).
  • Mount a drive manually: `sudo mount /dev/sdXN /mnt/mountpoint`; for a permanent mount at boot, add an entry to `/etc/fstab` (back it up first — a bad fstab entry can stop the system from booting).

Never repartition or format a drive that's currently mounted and in use — unmount it first (`sudo umount /dev/sdXN`), and always double-check the device name before running any destructive command.

Why it matters

Running out of disk space silently breaks updates, app installs, and sometimes the desktop session itself (a full home partition can prevent login) — knowing how to quickly find what's consuming space avoids a much more confusing troubleshooting session later.

Best practices

  • Keep at least 10-15% of your root/system partition free — package managers and journaling filesystems both need working room.
  • Use `lsblk -f` before formatting anything to double-check UUIDs and confirm you're targeting the right device.
  • Prefer ext4 or btrfs for the system partition on most desktop setups — btrfs adds native snapshot support if you want that later.

Common problems and fixes

"No space left on device" but `df -h` shows free space
You've likely run out of inodes, not space — check with `df -i`; this is common with directories containing huge numbers of small files (e.g. mail spools, node_modules).
External drive doesn't mount automatically
Check it's formatted with a filesystem Linux reads natively (ext4, exFAT with `exfatprogs` installed, or NTFS with `ntfs-3g`) — some distros need the exFAT/NTFS driver packages installed separately.

Tips and tricks

  • `ncdu` gives an interactive, much faster way to drill into what's eating disk space than repeated `du` commands.

Frequently asked questions

Is it safe to resize a partition without losing data?

Shrinking or growing a partition is generally safe with modern tools like GParted as long as you don't interrupt the process, but always back up first — a power loss mid-resize can corrupt the filesystem.