OrbStack disk usage on a Mac is easy to misread. All of OrbStack's data lives in one file, data.img, and Finder can show that file as 8 TB, more than most Macs can hold.
It isn't taking 8 TB. It's a sparse file: 8 TB is the most it may grow to, and it takes only the space your containers, images, volumes and Linux machines use.
To see the real number, select the file in Finder and choose File › Get Info: the size on disk is the one that counts. OrbStack's own Settings show how much it holds too, and its lists sort images and volumes by size.
To get space back, delete what you don't need inside OrbStack: old images, stopped containers, volumes you're sure about and Linux machines you made for a test. OrbStack's documentation says the file shrinks by itself as you delete data.
Never move data.img to the Trash to fix a full disk. It holds every container, image, volume and machine at once, and whatever you made inside a volume or a machine goes with it. The sections below explain the file, what's inside it, and each safe way to make it smaller.
Why OrbStack shows an 8 TB file
OrbStack is an app for running Docker containers and Linux machines on a Mac. Like every tool of its kind, it runs them inside a Linux virtual machine, and that machine needs a disk of its own.
What is data.img?
OrbStack stores that disk as a single file, data.img, in ~/. Inside the virtual machine it's an ordinary Linux disk. Docker's engine keeps images, containers, volumes and the build cache on it, and each Linux machine's files live there too.
From your Mac's side, it's one file in a folder you rarely open. The catalog's entry for OrbStack data describes it the same way: the disk image that holds OrbStack's containers, images, volumes and Linux machines.
Why does OrbStack make it 8 TB?
OrbStack's FAQ says the large size lets it manage the disk dynamically, so you never have to choose a disk size up front, or worry about having too much or too little. The 8 TB is a ceiling, set so high that your Mac runs out of real space long before the file reaches it.
That's a different approach from Docker Desktop, which creates its disk at a limit you set in its settings. OrbStack's documentation describes disk limits only for individual Linux machines, not for its Docker data, which simply grows and shrinks with what's inside.
What makes a file sparse?
Apple's documentation for APFS, the Mac's file system, explains it plainly: in a sparse file, blocks are stored on disk only when something is written to them. Files with large empty stretches, such as disk images, take far less space than their size suggests.
So data.img has two sizes. Its apparent size, 8 TB, is how large the file says it is. Its size on disk counts only the blocks really stored, which is what your containers and machines hold. OrbStack's FAQ puts it in one line: the file takes only as much space as you use.
How much space does a fresh install use?
Very little. OrbStack's efficiency page says a fresh install uses less than 10 MB of disk space, and that usage rises and falls as needed. Everything above that is what you've pulled, built and created since.
- The size data.img reports8,000 GB
- Space container tools typically use10–150 GB · Review first
The 8 TB size is from OrbStack's FAQ. The typical range is for container tools and virtual machines on Macs that use them, from the research behind the app's catalog; many Macs use far less, and a fresh OrbStack install uses under 10 MB.
The gap between the two bars is the whole story. The first is a promise of room; the second is the range the catalog's research found on Macs that use container tools.
How to check OrbStack disk usage on a Mac
There are three places to look, and each answers a slightly different question. Finder tells you what the file costs your Mac, OrbStack tells you what's using it, and Storage settings tells you where macOS counted it.
Get Info in Finder
- In Finder, choose Go › Go to Folder.
- Paste the folder path from the section above and press Return.
- Select data.img, then choose File › Get Info, or press Command-I.
- Read the Size line. The first figure is the apparent size, about 8 TB. The figure in parentheses, marked "on disk", is the space the file really takes.
Look, but don't move, rename or open anything in that folder. The steps are the same in macOS 27 Golden Gate and macOS 26 Tahoe, according to Apple's Get Info pages for each version.
OrbStack's own storage view
OrbStack's Settings have a Storage section. Its release notes say version 2.2.0, from June 2026, began showing storage use there as a capacity bar, and version 2.2.2 improved those bars. It's the quickest view of how much OrbStack holds, without touching its folder.
The app's lists go further. Its release notes describe sorting images and volumes by size, and a refresh button for volumes' disk usage. Those lists show what's using the space, which Finder can't see inside one file.
Storage settings and System Data
macOS doesn't know what data.img is. In System Settings › General › Storage, it's counted as System Data, which Apple describes as files that don't fall into the other categories, and whose contents you can't manage there.
So a rise in System Data after a week of builds is often OrbStack or another container tool. Storage settings sits in the same place in macOS 26 and 27; before macOS Ventura, the same view was under About This Mac › Storage.
Why do the numbers disagree?
Each tool measures something different, and none of them is wrong. The trick is knowing which one answers your question.
| Where you look | What it shows for OrbStack | Good for |
|---|---|---|
| Finder's list view | Often the apparent size, about 8 TB | Nothing about real usage |
| Finder's Get Info | The apparent size, and the size on disk in parentheses | What the file costs your Mac |
| OrbStack's Settings, Storage | Storage use as a capacity bar | How much OrbStack holds |
| OrbStack's image and volume lists | Each item's size, sortable | Finding the largest items |
| Storage settings | A share of System Data | Seeing that something grew |
OrbStack's figure and Finder's on-disk figure won't match exactly. OrbStack counts the data inside its disk, while Finder counts the blocks the file holds on your Mac, and the two are measured differently.
Reading the numbers: an example
Here's an illustration, not a measurement. Say Get Info shows data.img at about 8 TB, with 46 GB on disk. The 8 TB means nothing for your free space; 46 GB is the figure to work with.
Next, open OrbStack and sort its images and volumes by size. If old images account for most of it, deleting them costs only a download later. If one database volume is the largest item, it's the one to keep or back up before anything else.
Where OrbStack keeps its files
Most of OrbStack's space is in data.img, but OrbStack touches a few other places on your Mac. Only one of them takes real space.
| Location | What it holds | Takes real space? |
|---|---|---|
~/Library/Group Containers/HUAQ24HBR6.dev.orbstack/data | data.img: Docker data and Linux machines | Yes, its size on disk |
~/OrbStack | A live view of containers, images, volumes and machines | No |
~/.orbstack | Settings such as the Docker engine's config, and command-line tools | A little |
/Applications/OrbStack.app | The app itself | The app's size |
/usr/local/bin | Links to OrbStack's command-line tools, if you allowed admin | No, they're links |
| Your project folders | Files you share with containers through bind mounts | They stay on your Mac |
What is the ~/OrbStack folder?
While OrbStack is running, ~/ gives you read-write access to the files in containers, images, volumes and machines. OrbStack's FAQ says it's only a view: it takes no space on disk, and data isn't really stored there.
Containers appear under docker/containers, images under docker/images, volumes under docker/volumes, and each Linux machine under its own name. You can open the folder from Finder's sidebar, or from the folder button next to an item in OrbStack's window.
Because it's a view, two things follow. Deleting a file there deletes it inside OrbStack, so treat it with the same care as the data itself. And a tool that adds up folder sizes and walks into it can count the same data a second time, on top of data.img.
If the extra sidebar item bothers you, OrbStack's settings include Hide OrbStack volume, which hides it from the desktop and Finder's sidebar. The folder stays reachable at its usual path.
Why do older guides mention ~/.orbstack/data?
Older versions of OrbStack kept data.img in ~/, and backup vendors' notes and forum posts still name that folder. The current documentation names the group container in your Library folder instead.
The hidden ~/ folder is still used. It holds OrbStack's command-line tools and its configuration, such as the Docker engine's settings, so leave it alone while you use OrbStack.
Are files you mount from your Mac inside data.img?
No. When a container uses a folder from your Mac through a bind mount, such as a project folder, the files stay where they are on your Mac. They aren't copied into data.img, and deleting OrbStack data never touches them.
Volumes are the opposite. OrbStack's documentation says data in volumes is stored directly on the Linux side, which is why volumes are faster for containers, and why they live inside data.img.
What fills OrbStack's disk
Everything inside data.img falls into a few kinds of data, and they differ a lot in what it costs to lose them. Images come back with a download. A volume or a Linux machine may hold work that exists nowhere else.
| What | What it is | If you delete it |
|---|---|---|
| Images | The templates containers start from | Downloaded or built again when needed |
| Containers | Running or stopped copies of images | Files written inside them are gone |
| Volumes | Data containers keep, such as databases | Gone for good |
| Build cache | Saved steps from earlier image builds | The next build takes longer |
| Linux machines | Full Linux systems with their own files | Gone for good, with everything installed |
Images
An image is a stack of layers, and each new version you build or pull adds layers. Old versions of your own images, base images from projects you've finished, and images you tried once all stay until you remove them.
Images are the cheapest thing to remove, because a registry or your Dockerfile brings them back. Docker won't remove an image a container still uses, so stopped containers can keep old images alive.
Docker's documentation calls an image dangling when it has no tag and no container uses it. Rebuilding an image under the same tag leaves the old one behind like that, so a project you rebuild often collects them quickly.
Building for more than one processor type adds up too. On Apple silicon, OrbStack runs Intel images through Rosetta, and an Intel variant of an image is a separate image that takes its own space.
Containers
A container is a running or stopped copy of an image, with a thin layer for anything written inside it. Stopped containers keep that layer. Files a program wrote inside the container, rather than to a volume or a bind mount, go with it when you delete it.
Containers from Compose projects you no longer run are the usual leftovers. OrbStack groups them by project, which makes them easy to spot and remove together.
Volumes
Volumes are where containers keep data meant to last: local databases, uploaded files, caches you chose to keep. Nothing brings a deleted volume back, so check what's inside before you remove one.
OrbStack can export a volume to a compressed archive and import it later, and copy a volume into a new one. Its documentation describes both with its command-line tool and says volume copies use very little extra space until files change.
Build cache
Each image build saves its steps, so the next build can skip work it has already done. OrbStack's documentation says unused build cache is deleted automatically to save space, which keeps it from growing without end.
Clearing it all is the documented step when you're low on space. That's done with Docker's own command-line tool; OrbStack's documentation doesn't describe a button for it in the app.
The Builds tab that arrived in version 2.2.3 shows the history, steps and logs of your builds. It helps you see what you've built, but the release notes don't describe clearing the cache from it.
Linux machines
A Linux machine is a full system, with its own installed packages, home folder and files. A machine you made for an afternoon's test can keep several gigabytes for years. One you work in every day may hold work that exists nowhere else.
OrbStack's documentation says copying a machine doesn't double the space it takes, because data is copied only when it changes. Exporting a machine to a file is the documented way to back it up or move it, again with OrbStack's command-line tool.
Kubernetes
OrbStack can also run a small Kubernetes cluster for development. Its documentation says the cluster uses the same container engine as the rest of OrbStack, so images you build are available to it without a second copy. Its workloads live in the same disk as everything else.
How to free space in OrbStack
The rule is simple: delete data in OrbStack, and let OrbStack shrink the file. You never need to touch data.img itself.
What's a safe order to work in?
- Measure. Note the size on disk in Get Info, then sort OrbStack's images and volumes by size.
- Remove containers you no longer run, especially stopped ones from old Compose projects.
- Remove images nothing uses, starting with the largest and the oldest.
- Remove Linux machines you made for a test and no longer need.
- Back up, then remove volumes you're sure about, one at a time.
- Check again. Get Info on data.img should show a smaller size on disk.
The order starts with what costs least to lose and ends with what can't be replaced. Stop as soon as you have the space you need; there's nothing to gain from emptying everything.
How do you delete containers and images in the app?
In OrbStack's window, select the containers or images you don't need and delete them. Its release notes say Command-Delete deletes the selected items and, since version 2.2.2, asks for confirmation first; Command-Option-Delete skips that question.
The menu bar item can delete containers and Compose projects too, without opening the main window. Delete containers first: an image a container still uses won't go until the container does.
How do you remove volumes safely?
Open the volume's files first. Each volume appears in ~/ under docker/volumes, so you can look inside with Finder and copy out anything worth keeping before you delete the volume.
If you might need the whole volume again, export it first, or keep the project's seed data or database dump somewhere you control. Then delete it in OrbStack's window, one volume at a time, rather than all unused volumes at once.
How do you remove a Linux machine?
Open the machine's files from ~/, under the machine's name, and copy out anything you made there. Then delete the machine in OrbStack's window. Everything installed in it, and every file in its home folder, goes with it.
What does Docker's own cleanup remove?
OrbStack runs an unmodified Docker engine, so Docker's prune commands work there as they do anywhere. Many guides suggest them, so it helps to know what each one takes.
| Docker's cleanup | What it removes | What it leaves |
|---|---|---|
| Image prune | Dangling images | Tagged images, even unused ones |
| Image prune, all | Every image no container uses | Images in use |
| Container prune | Stopped containers | Running containers |
| System prune | Stopped containers, unused networks, dangling images, unused build cache | Volumes and tagged images |
| System prune, all | The above, plus unused tagged images | Volumes |
Volumes are never part of the default cleanup, according to Docker's documentation. That's deliberate: they're the one kind of Docker data that can't be downloaded again. OrbStack's window covers the same ground, item by item, without Terminal.
Why didn't the file get smaller?
A few things can hold on to the space for a while:
- A container still uses the image, so the image wasn't really removed. Delete the container first.
- Time Machine's local snapshots still hold the old blocks of data.img. They expire by themselves; the guide to Time Machine local snapshots explains how they work and how to remove them sooner.
- You're reading the wrong number. Finder's list view keeps showing about 8 TB whatever happens inside.
Starting over: clearing Docker data or everything
OrbStack's settings documentation lists two storage actions that remove data wholesale. Both are irreversible, so they're the last thing to try, not the first.
What does clearing Docker data remove?
The documentation calls it Clear Docker data: it resets and deletes all of OrbStack's Docker data. That means every container, image, volume and the build cache. Linux machines aren't part of Docker data, so they stay.
What does clearing all data remove?
Clear all data is a factory reset. The documentation says it deletes all data, including all Docker data and all Linux machines. OrbStack starts again as if newly installed.
The documentation describes both actions with OrbStack's command-line tool and doesn't name a button for them in the app. Deleting items one by one in OrbStack's window reaches the same result with more control, and nothing goes that you didn't choose.
When is starting over worth it?
| Situation | Better choice |
|---|---|
| A few large images or old projects | Delete them one by one |
| Years of images, containers and old builds, nothing worth keeping | Clearing Docker data |
| You only use Linux machines, not Docker | Delete images and containers; keep the machines |
| You want a clean slate, machines and all | Clearing all data, after exporting what you need |
| You're leaving OrbStack | Uninstall it, below |
Before either reset, export volumes and machines you might want back. Afterwards, the first container or build downloads its images again.
Why you should never delete data.img
Dragging data.img to the Trash looks like the fastest fix for a full disk. It's the one move to avoid.
What happens if you move it to the Trash?
Every container, image, volume and Linux machine goes at once, including databases in volumes and files in machines. Nothing inside can be picked out afterwards; it's one disk image.
It doesn't free 8 TB either. Deleting a file frees what it takes on disk, so you'd get back the same space as deleting everything in OrbStack's window, with no chance to keep the parts you need. And it only frees anything once you empty the Trash.
Is it safe to delete OrbStack's group container?
Only if you're uninstalling OrbStack and don't need its data. Everything OrbStack keeps is in that folder's data folder, so removing it is the same as clearing all data.
Never remove the Group Containers folder itself. It holds the shared data of many other apps, and macOS and those apps rely on it.
How do you uninstall OrbStack completely?
OrbStack's install page gives the steps. Quit OrbStack, then move it from the Applications folder to the Trash. To remove all its data too, move ~/ and OrbStack's folder in Group Containers, HUAQ24HBR6.dev.orbstack, to the Trash.
After uninstalling, Docker's command-line tool may still point at OrbStack and fail to connect. OrbStack's FAQ covers the fix: switching Docker's context back to its default, or to Docker Desktop's if you return to it.
Backups, new Macs and other drives
Sparse files behave well on APFS, but not everywhere. Backups, migrations and copies are where data.img's apparent size can cause real trouble.
Does Time Machine back up data.img?
It can, and that's fine. OrbStack's FAQ says Time Machine supports sparse files, so the 8 TB size doesn't affect your backups. What's backed up is the data really in the file.
Should you exclude OrbStack from backups?
That depends on what's in it. If OrbStack holds only images you can pull again, excluding it saves backup space. If a volume or a machine holds your only copy of something, keep it in the backup, or export that data and back up the export instead.
To exclude it from Time Machine in macOS 27 or macOS 26:
- Choose Apple menu › System Settings, click General in the sidebar, then click Time Machine.
- Click Options.
- Click the Add button, then choose OrbStack's data folder in Group Containers.
- Click Done.
Apple notes that excluded items still appear in Time Machine's local snapshots. Some third-party backup apps, such as Backblaze, complain about data.img; OrbStack's FAQ suggests excluding the file from them.
What about moving to a new Mac?
OrbStack's FAQ warns that Migration Assistant doesn't support sparse files, even though Time Machine does. Before you move to a new Mac with Migration Assistant, OrbStack says to delete data.img first, or to back it up with a command-line archive tool.
In practice, export the volumes and machines you care about first. On the new Mac, install OrbStack, import them, and pull your images again.
Why can copying data.img to some drives fail?
Apple's APFS documentation notes that HFS Plus, and other formats without sparse files, store every block of a file, empty or not. Copied to such a drive, data.img could ask for its full apparent size. OrbStack's 1.6 release notes mention a Time Machine exclusion added to prevent problems on HFS Plus.
There's no reason to copy the file by hand anyway. Export what you need from OrbStack instead.
OrbStack and Docker Desktop on the same Mac
Many people try OrbStack after Docker Desktop, and some keep both. The two keep separate disks, so data in one takes no space in the other, and leftovers in either stay until you remove them.
| OrbStack | Docker Desktop | |
|---|---|---|
| Where the disk lives | ~/Library/Group Containers/HUAQ24HBR6.dev.orbstack/data | ~/Library/Containers/com.docker.docker/Data/vms/0/data/Docker.raw |
| Size the file reports | About 8 TB | The disk usage limit you set |
| How it shrinks | By itself, as you delete data | Docker returns freed space to the Mac |
| Disk limit setting | Per Linux machine only | Settings › Resources › Advanced |
| Linux machines | Yes, in the same disk | No |
Does migrating from Docker Desktop double the space?
For a while, yes. OrbStack offers to migrate Docker Desktop's containers, volumes and images when you first open it, or later from File › Migrate Docker Data. Its install page says this makes a copy of your old data.
So after a migration, the same images and volumes sit in both disks. Once everything works in OrbStack, its install page says you can reset Docker Desktop's data. The post on Docker Desktop disk space explains what that removes and how to do it from Docker Desktop's own settings.
Can you limit how much disk OrbStack uses?
For Linux machines, yes. OrbStack's documentation says you can limit a machine's memory, CPU and disk when you create it, or later in the machine's settings in the app; version 2.2.0 added per-machine disk limits.
For Docker data, the documentation describes no limit. Its size is up to you: what you keep is what it takes.
Does OrbStack use less disk space than Docker Desktop?
Neither tool's documentation compares the two on disk space, and the images and volumes you keep are what fill either one. The real difference is the ceiling: Docker Desktop's file reports the limit you set, OrbStack's reports 8 TB, and neither is the space it really takes.
Keeping OrbStack from filling your Mac again
A container tool grows the way a downloads folder does: a little at a time, from things you meant to clean up later. A few habits keep it in check.
- Check OrbStack's storage view once a month, and sort images by size.
- Delete stopped containers when you finish with a project, not months later.
- Remove images for projects you've finished, and old versions of your own images.
- Delete Linux machines you made for a one-off test as soon as the test is done.
- Keep seed data and database dumps in your project, so volumes are easy to rebuild.
- After moving from Docker Desktop, reset its data once OrbStack works, or uninstall Docker Desktop.
- Keep OrbStack up to date. Version 2.2.4, from October 2026, fixed crashes and a stall at "Starting" on macOS 27.
Will freeing OrbStack's space make your Mac faster?
No. It frees disk space, and that's all. Deleting images and volumes doesn't make your containers or your Mac run faster.
Its documentation's advice for lower CPU use is to stop containers you aren't using, which costs nothing on disk. Space is what you get back from deleting, and on a nearly full disk, that's what matters.
How the app does it
Wombit explains OrbStack's data like everything else on the disk. Select its folder in the map or the list, and the inspector says what it is and how safe it is to remove, from the catalog's entry. Sizes are space on disk, so data.img counts as what it really takes, not 8 TB.
The entry is Review first, because volumes and Linux machines can hold files you made. It's explained only: the app shows OrbStack's own steps, as above, and never moves data.img or its folder to the Trash. Deleting containers, images, volumes and machines is left to OrbStack.
~/
Library/ Group Containers/ HUAQ24HBR6.dev.orbstack/ data The disk image that holds OrbStack's containers, images, volumes and Linux machines.
Review first · Explained only: the app shows you how
~/
Library/ Containers/ com.docker.docker/ Data/ vms/ 0/ data/ Docker.raw Docker Desktop disk image (Docker.raw)
The virtual disk where Docker Desktop keeps all your images, containers, volumes and build cache.
Usually safe · Runs docker --context desktop-linux builder prune --force
The app reads only names, sizes and dates, and file names and paths never leave your Mac. Seeing all of this is free. Cleanup of the items the app does remove is PRO, one $4.99 payment with lifetime access. Every Pro tool's review is free to open, so you see what would go and why before you buy.
Frequently asked questions
Why is OrbStack's data.img 8 TB?
It's a sparse file, the virtual disk of OrbStack's Linux machine. 8 TB is the most it may grow to, chosen so OrbStack can manage the disk without a fixed size. It takes only the space your containers, images, volumes and Linux machines really use.
Can I delete data.img to free up space?
You can, but it removes every container, image, volume and Linux machine at once, including databases and files you made. It also frees only what the file takes on disk, not 8 TB. Delete what you don't need in OrbStack's window instead, and the file shrinks by itself.
How do I see how much space OrbStack really uses?
Select data.img in Finder and choose File › Get Info: the figure in parentheses, marked on disk, is the real space. OrbStack's Settings also show storage use as a capacity bar, and its lists sort images and volumes by size.
Where does OrbStack store Docker images on a Mac?
Inside data.img, in OrbStack's folder in your Library's Group Containers folder. Older versions kept it in a data folder inside the hidden .orbstack folder in your home folder. While OrbStack runs, you can browse images' files in the OrbStack folder in your home folder, which is only a view and takes no space.
How do I reset OrbStack and delete all its data?
OrbStack's settings documentation lists Clear Docker data, which removes containers, images and volumes, and Clear all data, a factory reset that also removes Linux machines. Both can't be undone, so export volumes and machines you need first. Deleting items one by one in the app gives you more control.
Does OrbStack give space back when I delete containers?
Yes. OrbStack's FAQ says data.img automatically shrinks when you delete data. If the size on disk doesn't drop, check that no container still uses the image you removed, and remember that Time Machine's local snapshots can hold old data until they expire.
Should I exclude OrbStack from Time Machine?
If OrbStack holds only images you can download again, excluding its data folder saves backup space. If volumes or Linux machines hold your only copy of something, keep them backed up. Time Machine handles the sparse file correctly, so the 8 TB size itself isn't a problem.
Is the ~/OrbStack folder taking up space?
No. OrbStack's FAQ says it's a view of the data in containers, images, volumes and machines, and it takes no space on disk. Deleting files there does delete them inside OrbStack, though, so treat it with the same care.
Sources
- Get file, folder, and disk information on Mac · Apple
- About Apple File System · Apple
- Exclude files from a Time Machine backup on Mac · Apple
- Frequently asked questions · OrbStack
- Settings · OrbStack
- Install OrbStack · OrbStack