Four pages show what lives on DoCatz’s engine besides containers: Images (mod+2), Volumes (mod+3), Networks (mod+4) and Builds (mod+5). Each one tells you what takes the space and who uses it, and nothing is removed before you have seen the list. They need the engine running; when it is not, they offer to start it.
Images
The header shows how many images there are and their total size, a pull box and Clean up….
- Pull — type an image, such as
postgres:17, and press Pull. The download streams into a panel below. - Filter — narrows the list.
| Column | Shows |
|---|---|
| Image | Its tags; an image without a tag shows a dimmed <none> |
| ID | The short image ID |
| Size | Its size on disk |
| Created | How long ago the image was built |
| In use | 2 containers, or unused |
Hover a row for Remove. It asks Remove postgres:17?:
- an unused image — It downloads again when something needs it.
- an image containers use — they must be removed first, or you can Force remove it (the containers keep running on it until they are removed).
Volumes
Volumes hold your data — a database’s files, uploads, caches — and they outlive the containers that use them.
| Column | Shows |
|---|---|
| Volume | Its name |
| Project | The compose project it belongs to |
| Size | How much it holds |
| Used by | The containers that use it |
Remove is greyed out while a container uses the volume (Remove the containers using it first). Removing asks Remove this volume? — The data inside it is gone for good — and you type the volume’s name to go ahead.
Need what is inside first? Open a container that mounts it and use the Files tab to
save a folder as a .tar.
Networks
| Column | Shows |
|---|---|
| Network | Its name, with a Docker’s own badge for bridge, host and none, and internal for a network with no way out |
| Driver | bridge, host, … |
| Subnet | Its address range |
| Project | The compose project that made it |
| Containers | Who is on it |
Remove is there only for networks you (or a compose project) made that no container is on; it confirms with No
container is on it. Docker’s own bridge, host and none are never removed.
Clean up
Clean up… is on the Images, Volumes and Networks pages and on each row of Disk usage. It always lists exactly what would go, with sizes, and only then offers Remove 12 (or however many there are). When there is nothing to remove, it says so.
| Clean-up | What goes | Note |
|---|---|---|
| Remove stopped containers | Containers that have exited, were created but never started, or are dead | Their images and named volumes stay. |
| Remove unused images | Every image no container uses, running or stopped — not only untagged ones | They download again when needed. |
| Remove unused volumes | Every volume no container uses | The data inside them is gone for good. You type delete to go ahead. |
| Remove unused networks | Networks you made that no container is on | Docker’s own stay. |
| Clear the build cache | Build cache no build is using | The next builds take longer once. |
When it is done, DoCatz says how many were removed and how much space was freed.
Builds
Builds is your build history: every docker build and every compose build on DoCatz’s engine, read from BuildKit
(docker buildx history). With none yet it says No builds yet. Every docker build and compose build on DoCatz shows
up here.
Each build in the list shows its status, how long ago it ran, how long it took and how much of it came from the cache. Click one for its page:
- Build — the context, the Dockerfile and target, the platforms, the base images, the result and when it started.
- Log — the full build log, with Copy.
- Show context opens the build’s folder.
- Removing a build asks Remove this build from the history? — Only the record and its log go; the image it made stays.
Builds use DoCatz’s own docker and buildx; until the engine has started once, the page says docker and buildx are
not installed yet — start the engine once.
To build for several platforms at once, or to run an amd64 image on an ARM machine, see the Builds group on the Commands page.
Last updated 2026-11-03