Docker Sandbox images take a huge amount of space for no reason

[sirknigget (Omer Gilad)]

I started from a very simple shell sandbox, where I manually installed Claude Code.
The first template save resulted in a 1.5GB image.

After that, I proceeded to install some very minimal bash tools, such as direnv, and did some custom bash environment configuration. I also added my rules/skills/hooks/MCPs to Claude.
On the 2nd template save, I got a 4GB image. No idea what added those unnecessary 2.5GB.
I attempted to inspect it using Docker Desktop but it doesn’t show any meaningful info.

Is this a known issue?
Or is there any way for me to inspect what’s bloating my image?

[rimelek (Ákos Takács)]

@sirknigget

Is this a known issue?

It is

Config options to reduce Docker.raw for docker sandboxes on Docker Desktop for Mac

I tried it with Codex as well and I got 10 GB after pulling the image like I got with Kiro. It could still increase any time youdo something in the sandbox that needs to write the filesystem. Sometimes writing different parts of the disk is better so it is evenly used during the years. I think this happens with SSDs, but when using a virtual disk without limited size, it can make your disk grow until it fills up your disk. I shared this feedback internally with Docker, but I see you also opened…

do you also use Docker Desktop on macOS or any machine with SSD?

[sirknigget (Omer Gilad)]

Yes, correct. Docker Desktop on MacOS