OrbStack needs a licence for work, so I tuned Colima itself

TL;DR: I wanted to move from Colima to OrbStack. OrbStack needs a paid licence for work use, and my containers are mostly for work, so I stayed on Colima and tuned it. Rosetta made x86 containers about 5x faster, a careful prune gave back 28 GB on the Mac, and I cleaned up what an old OrbStack install had left behind. All the commands are below.

How I got here

I started with Docker Desktop, like most people on a Mac. It was eating a lot of CPU and memory, even when I was not running anything heavy, and the whole machine felt it. The fan was running more than my containers.

I was not the only one. People reported the VM service sitting at 90% CPU with no container running, com.docker.krun taking close to 10 GB of RAM for one container, and CPU spikes that made even the browser lag on an M1.

So I moved to Colima, and that was a good decision. Colima is a small Linux VM and a CLI. No GUI, no extensions marketplace. CPU and memory go in one YAML file, and colima stop gives the CPU and memory back to the Mac when I do not need it. It is MIT licensed also, so there is no pricing page.

Small side note: Docker Desktop itself is free only for small businesses, fewer than 250 employees and less than $10 million in yearly revenue. Bigger companies need a paid subscription. Keep that in mind, licences come back later in this post.

So Colima was working fine. Nothing was broken.

But I like trying new things. When a new tool shows up, I read about it first, and if it gives me a promising impression, I try it out.

OrbStack is one of those tools I kept reading about. What caught my eye was how it handles files and resources. The docs talk about two-way file sharing on a tuned VirtioFS, starting in 2 seconds, and memory that is taken only when needed and given back to macOS when it is not. Since I restart containers all day, that sounded good to me.

So I thought, why not give it a proper try.

My setup is an Apple M4 with 24 GB of RAM, running Colima with the Docker runtime. On a normal day it runs four compose projects and seventeen containers for my day job, plus some side projects.

I had actually installed OrbStack once before, a while back, and removed it. Why, I do not remember. "Just testing, no reason" is the honest answer.

This time I wanted to do it properly. Check what I have, check what OrbStack gives, then switch.

What OrbStack gives

OrbStack's own comparison page against Colima is mostly ticks on its side and crosses on Colima's:

• Dynamic memory. The VM takes RAM when it needs it and gives unused memory back to macOS. Colima gives the VM a fixed size, 8 GiB in my case, and the comparison page marks dynamic memory as missing in Colima.
• Two-way file sharing. Colima does it one way. The docs also suggest volumes over bind mounts for the best speed, which is good advice for any Docker setup on a Mac.
• Container domains and automatic HTTPS. Every container gets a name like container-name.orb.local, with a local CA and certificates set up for you. No /etc/hosts edits.
• Fast x86 emulation through Rosetta. The page marks Colima's Rosetta support as "Experimental".
• Fast startup, low CPU and power use, and a native Mac app. Colima has no app at all.

It is the vendor's own page, but each point has its own docs page behind it. It is a strong list, and I was more or less ready to switch.

Then I opened the pricing page.

The licence page

OrbStack is "always free for personal use". The licensing page then says:

Freelance, business, and commercial users of OrbStack must purchase a license for each user.

Pro is $8 per user per month, billed yearly as $96. Installing it gives a 30-day Pro trial, and after that it drops to the free plan, which is personal use only.

My containers are mostly for my day job, so that is commercial use. The question was not "is OrbStack better?" anymore. It was "who pays for this?".

My answer was "not paying".

$96 a year is not a big amount. But Colima was already working, and I had not even checked how much of what I wanted from OrbStack I could get from Colima for free. So I checked that first.

Step 1: Check what you have

Three commands give most of the picture:

# the VM: cpu, memory, disk colima list # which docker context is active docker context ls # where the disk space went docker system df 

And the Colima config:

grep -vE '^\s*#|^\s*$' ~/.colima/default/colima.yaml 

These were the lines that mattered for me:

vmType: vz mountType: virtiofs mountInotify: true rosetta: false binfmt: true 

virtiofs is already the fastest mount option Colima has (its own config says so), so file mounts were fine. rosetta: false was the problem. Every x86 (amd64) image I ran was going through QEMU emulation, which is slow, and I have a few amd64 images in my stack.

docker system df showed this:

TYPE TOTAL ACTIVE SIZE RECLAIMABLE Images 69 13 40.85GB 34.92GB (85%) Local Volumes 191 11 33.16GB 7.574GB (22%) 

69 images, only 13 in use. If you have been ignoring that RECLAIMABLE column for a long time, you know what comes next.

docker context ls also had an orbstack context still in the list, pointing to a socket that did not exist anymore. I had removed the OrbStack app long back, but a few bits of that install were still there. I come back to that in step 6.

Step 2: Measure before changing anything

Without a before number, "it is faster now" is just a feeling. I ran a small CPU loop in an amd64 Alpine container, three times:

# force x86, run a loop, print the arch to confirm it is really x86 for i in 1 2 3; do time docker run --rm --platform linux/amd64 alpine \ sh -c 'i=0; while [ $i -lt 300000 ]; do i=$((i+1)); done; uname -m' done 

Under QEMU each run took about 7 seconds: 6.81, 6.94 and 7.31. Note your number down.

Step 3: Prune, but carefully

This is the step where people lose data, so go slow here.

I removed unused images and the build cache. I did not touch volumes, since volumes are where the databases live.

# images not used by any container docker image prune -a -f # build cache, it gets rebuilt when needed docker builder prune -a -f # volume count should be the same as before docker volume ls -q | wc -l 

There is no docker system prune --volumes here, and that is on purpose. Do not run it on a machine with data you care about.

Images went from 69 to 13, about 41 GB down to 13 GB. Build cache went to zero. The volume count was still 191, so no database was touched.

Step 4: Turn on Rosetta

Rosetta in Colima needs the vz VM type and Rosetta installed on the Mac. If you have ever run an Intel app on an Apple Silicon Mac, it is probably installed already. If not:

softwareupdate --install-rosetta --agree-to-license 

Then change the flag in ~/.colima/default/colima.yaml:

rosetta: true 

And restart the VM:

colima stop colima start 

On start, this warning showed up a few times (I was on Colima 0.9.1):

Both top-level 'rosetta' and 'vmOpts.vz.rosetta' are configured. Using vmOpts.vz.rosetta. Top-level 'rosetta' is deprecated. 

I thought I had edited the wrong thing. So I asked the VM itself which emulator it is using, instead of trusting the config file:

# should say enabled colima ssh -- cat /proc/sys/fs/binfmt_misc/rosetta # should say disabled colima ssh -- cat /proc/sys/fs/binfmt_misc/qemu-x86_64 

Rosetta was enabled and QEMU was disabled, so the setting works. The warning comes from Lima, the VM layer Colima runs on, not from Colima. Colima's own config still uses the top-level rosetta key, so there is nothing to fix on your side.

Same benchmark again:

About 7 seconds down to about 1.3 seconds, roughly 5x faster, for one word in a YAML file. Fast x86 emulation was one of the items on OrbStack's list, and Colima could do it already. It was just set to false in my config.

Step 5: Count your containers after the restart

All four compose projects came back after the restart. But docker ps showed 13 running containers, and before the restart it was 17.

Four containers had stopped without any error.

docker ps -a --filter status=exited \ --format '{{.Names}}\t{{.Status}}' 

All four were standalone per-ticket web containers, not part of any compose project, with no restart policy (restart=no). Colima stopped them and nothing started them again. docker start brought them back:

docker start <container-1> <container-2> <container-3> <container-4> 

Any container you care about should have a restart policy: restart: unless-stopped in compose, or --restart unless-stopped on docker run. And after a VM restart, count the containers. Do not go by "looks fine".

Step 6: Clean up leftovers from an old install

This step is only for when the OrbStack app is already gone. If you have OrbStack installed and you use it, skip this step, there is nothing to clean.

I had removed the app outside Homebrew a long time back, so three small things stayed behind:

1. A line in ~/.zprofile that ran OrbStack's shell setup on every new terminal, and failed every time since the file was gone:

 # Added by OrbStack: command-line tools and integration source ~/.orbstack/shell/init.zsh 2>/dev/null || : 

The 2>/dev/null || : hid the failure, so I never noticed it. Take a backup of the file, then remove those lines.

1. The dead Docker context:

 docker context rm orbstack 

1. A Homebrew cask record for an app that was not there anymore. The normal brew uninstall --cask orbstack failed, since its uninstall script lives inside the app and the app was already gone. The force flag worked:

 brew uninstall --cask --force orbstack 

None of this was breaking anything. But a dead Docker context is the kind of thing that wastes a full evening one day, when some tool picks the wrong socket.

Step 7: Check the space on the Mac side

Pruning frees space inside the VM. The Mac does not always get it back, since the VM disk file does not always shrink. So check from the Mac:

du -sh ~/.colima 

Mine went from 76 GB to 48 GB. I also ran fstrim inside the VM, expecting a bit more:

colima ssh -- sudo fstrim -av 

It trimmed about 3.5 GiB, but du did not change. For me the prune had already done the job. You can skip fstrim if du already looks right.

Before and after

So, is Colima as good as OrbStack now?

No. OrbStack still has things Colima cannot do. Dynamic memory is the big one, my VM is still sized at a fixed 8 GiB whether I run the full stack or nothing. If that becomes a problem on a light day, I will stop Colima and start it smaller. CPU works the same way with --cpus:

colima stop # memory is in GiB; mine runs 4 CPUs and 8 GiB normally colima start --cpus 2 --memory 6 

You can also set them as cpu: and memory: in ~/.colima/default/colima.yaml and then run colima start. I have not needed that yet. There are no .orb.local domains either, and no Mac app.

What I got is the part Colima can do: x86 images on Rosetta instead of QEMU, and a much cleaner disk. That is a better-tuned Colima, not OrbStack.

If you use OrbStack for personal projects, it is free, so go for it. If your company pays for it, same. If you are about to pay for it yourself, check rosetta and docker system df in your Colima setup once before that. Some of what you want might be there already.

That is all from my side. If you know a Colima setting I missed, or you think the $96 is worth it, drop me a note. And before you close this tab, run docker system df once. That RECLAIMABLE column is waiting for you.