Disk usage

When a disk fills up, the question is always the same: what is taking the space? The Disk usage tab answers it. It scans a disk, shows the biggest folders first, and lets you open them one level at a time until you find the culprit — then delete it from the same screen.

First time: install the analyzer

Scans use ncdu, a fast, widely used disk usage analyzer. Click Install ncdu once per server. The panel downloads the official build and checks it against a known fingerprint before installing it, or installs your distribution's package if the server can't reach the internet. It takes a few seconds and uses no resources until you scan.

Installing needs an Operator, Admin or Owner. The server login needs root or passwordless sudo — without it, most system folders can't be read.

Scan a disk

Click Scan disk. If the server has more than one disk, you choose which one — or type a folder, such as /var/log, to scan just that.

A scan stays on one disk. Other disks mounted inside it (say /data inside /) show up as other disk and are not counted; scan them separately.

The scan runs on the server at low priority, so it doesn't slow down your apps. You can leave the tab or close the browser — it keeps going, and the progress bar picks up where it was when you come back. A disk with a few million files usually takes a minute or two. Cancel stops it.

Come back any time

The result is saved. Open the tab next week and it is still there, with Last scanned showing how old it is. Nothing touches the server until you click Rescan. A rescan replaces the old result only once it finishes.

Forget removes a saved result from the panel. It doesn't change the server.

Reading the result

• Folders — the biggest first. The bar shows each item's share of the folder it is in. Click the arrow to expand a folder in place, or click its name to open it (the path above the list takes you back up).
• N smaller items — to keep results quick, each folder lists its 100 largest entries and adds up the rest in one line.
• Small folders keep their size but not their contents. Use Open in File manager (the folder icon) to look inside them.
• A warning sign means part of a folder couldn't be read, so its real size may be larger.
• Largest files lists the 100 biggest files on the whole disk, wherever they are.

Deleting

Tick one or more items and click Delete selected, or use the bin icon on a row. You'll see exactly what will be removed and how much space it frees before anything happens. Deleting is permanent — there is no bin to restore from.

Some items show a lock instead, with the reason on hover. They are protected because deleting them would break the server or another program:

• anything directly under /, and the operating system (/etc, /boot, /usr, …)
• data other software manages: Docker's storage, database files, the package database — clean these up from the Docker tab, from inside the database, or with Packages → Autoremove
• users' home folders and SSH keys, and mount points

After a delete, the sizes on screen update and the result shows how much was freed since the scan.

A program that still has a deleted file open keeps using its space until it restarts. If the disk doesn't free up after deleting a large log, restart the service that writes it from the Services tab.

Every install, scan and delete is recorded in the Activity log.