Windows subsystem for Linux 2 (WSL2)

Set up Windows subsystem for Linux 2 (WSL2) for Linux development experience in Windows 10 and 11.

Instal WSL2

Open powershell with administrator privilege, run the following command in the host. This will install Ubuntu by default. Reboot after completion.

wsl --install

WSL2 post-install (optional) setup

Backup the virtual disk

To pack the virtual disk of the WSL system.

wsl --export Ubuntu .\Ubuntu\ext4.tar

To move the WSL virtual disk file to another disk (in this example, D:\), run the following commands in Windows ^{1 2}:

wsl --export Ubuntu .\Ubuntu\ext4.tar
wsl --unregister Ubuntu
wsl --import Ubuntu D:\Ubuntu\ .\Ubuntu\ext4.tar

Set default login user

Edit /etc/wsl.conf in the WSL. You may need to set the default user if you have moved the virtual disk file of the WSL distribution.

[user]
default=username

Host settings for WSL

Edit .wslconfig ³ in your Windows home directory (%USERPROFILE%).

For example,

[wsl2]
memory=20GB              # How much memory to assign to the WSL2 VM.
swap=8GB                 # How much swap space to add to the WSL2 VM. 0 for no swap file.
swapfile=C:\\temp\\wsl-swap.vhdx # Sets swap file path location, default is %USERPROFILE%\AppData\Local\Temp\swap.vhdx. Useful if your C drive has limited disk space.

Auto reclaim RAM and disk space

Edit .wslconfig ³ in your Windows home directory (%USERPROFILE%). ⁴

[experimental]
autoMemoryReclaim=dropCache  # Reclaim RAM usage
sparseVhd=true               # Reclaim virtual disk (vhd) usage

Maintenance

Update kernel

To (manually) update the WSL kernel, run the following commands with administrator privileges:

wsl --shutdown
wsl --update

Reclaim virtual disk space

Optimize-VHD

To reclaim disk space from virtual hard disks (VHDs), run the following commands with administrator privileges ⁵:

wsl --shutdown
Optimize-VHD -Path <path-to.vhdx> -Mode Full

Export and re-import

Alternatively, export the VHD as a tar file and reimport it again.

Caveats about WSL2

Poor filesystem performance across OSes

Cross-OS file access (e.g., accessing /mnt/c in WSL) is more than one order of magnitude (10x) slower than accessing natively (e.g., /home/user/).