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.

wsl --install

WSL2 post-install (optional) setup¶

Move the virtual disk¶

If you want to move the WSL virtual disk file to another disk (in this example, D:\), run the following commands in Windows¹²:

Tip

The following example will move the current WSL virtual disk to D:\Ubuntu\ext4.vhdx. You can change the distribution name (Ubuntu) and filesystem paths if necessary.

cd D:\
mkdir WSL
cd WSL
mkdir Ubuntu

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

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.

/etc/wsl.conf

[user]
default=username

Host settings¶

Edit .wslconfig ³ in your Windows home directory (Enter %USERPROFILE% in file explorer's location bar).

For example,

.wslconfig

[wsl2]
memory=20GB              # How much memory to assign to the WSL2 VM.
processors=4             # How many processors 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 (Enter %USERPROFILE% in file explorer's location bar). ⁴

.wslconfig

[experimental]
autoMemoryReclaim=dropcache
sparseVhd-true

Maintenance¶

Update kernel¶

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

wsl --shutdown
wsl --update

Reclaim virtual disk space¶

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

Alternatively, use diskpart (if Optimize-VHD is not found) ⁶

wsl --shutdown
diskpart
# open window Diskpart
select vdisk file="E:\ubuntu\ext4.vhdx"
attach vdisk readonly
compact vdisk
detach vdisk
exit

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 at least one order of magnitude slower than accessing the native (/home/user/file) files.⁷