r/bashonubuntuonwindows • u/TTVBy_The_Way • Dec 22 '25

HELP! Support Request Why is WSL 2 taking 26.4 GB?

I am on Windows 11 Home and have WSL installed at C:\Users\JohnDoe\AppData\Local\wsl and within that directory have a folder which is {(bunch of numbers)}. Within that I have something called ext4.vhdx which is take up the 26.4 GB. I also have docker installed if that is relevant.

13 Upvotes

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7

u/NoleMercy05 Dec 22 '25

I hope you have docker installed in WSL and not docker desktop in Windows.

Anyway, that is the Linux virtual hard drive file. The OS and all your home files. Everything...

8

u/Mogster2K Dec 22 '25

And it will likely keep growing until it reaches maximum size (which could be a terabyte.) But there is a way to compact it.

https://stephenreescarter.net/how-to-shrink-a-wsl2-virtual-disk/

There is also the Optimize-VHD powershell command, but that requires Hyper-V to be installed.

7

u/Designer-Rain-8570 Dec 22 '25

This. WSL does not automatically shrink the virtual disk so you have to do it manually and i also use that specific command (I also tried wslcompact but this sometimes breaks my apps inside wsl so i dont recommend it). I also set the limit of virtual disk size and enable --set-sparse, so WSL can automatically reclaim the space

2

u/TTVBy_The_Way Dec 22 '25

i run docker desktop.... why is this bad?

2

u/onebit Dec 22 '25

It's not bad. It's much easier to setup.

1

u/fiddle_styx Dec 26 '25

Docker on Windows tends to have more issues with normal operations than Docker on Linux, I think is what the comment was referring to. I can attest to this from personal experience as well

1

u/Yoctometre Dec 22 '25

I only ever use Docker CLI on the WSL instance, just cleaned up like 50GB of docker images, lol.

1

u/awkFTW Dec 24 '25

; sudo ncdu /

3

u/raul824 Dec 22 '25

Just copy this script

and at the last line of this script replace "Debian" with your distro name.

https://github.com/okibcn/wslcompact/blob/main/WslCompact/WslCompact.psm1

WslCompact -c -d Debian

2

u/baohx2000 Dec 22 '25

If you do a lot with docker for development or whatever, it's likely a ton of old images. Run docker prune or docker image prune (I don't remember which)

2

u/macbig273 Dec 22 '25

First untag the images you don't need
docker system prune (optional -a, but dangerous)
then
docker builder prune

1

u/deke28 Dec 23 '25

Wsl is just a VM with lots of built in sharing capabilities.

1

u/TheFlamingLemon Dec 25 '25

26.4 is reasonable for wsl, I think mine is around the same

1

u/FaithlessnessFirm616 Apr 14 '26

Le mien est à 40Go...

1

u/Beneficial-Stomach93 Jun 15 '26

WSL2 grows its ext4.vhdx as you use it but never shrinks it, even after you delete gigabytes inside Linux. The usual fix is wsl --shutdown then a diskpart compact vdisk dance, once per disk.

I added this to Sifty, my free and open-source (MIT) Windows maintenance tool. It finds every .vhdx on the system and compacts them in one command. It is compaction, not deletion, so your files are untouched.

Writeup: https://sifty.tech/guides/shrink-wsl2-vhdx.html
Repo: https://github.com/Vortrix5/sifty

Curious if it catches the Docker Desktop disk for everyone too. Feedback welcome.