in WSL2 with sparse vhd the storage usage does not shrink automatically, cannot compact it anymore manually

Question

I have 22H2 build 19045.3930 windows 10
WSL2 and I converted my vhd to be sparse once the feature was available to let it shrink on its own. However it does not seem to shrink when when I free up space and to make matters worse I cannot compress it manually any more either

optimize-vhd -Path ext4.vhdx -Mode full
gives
Error: 'The requested operation could not be completed due to a virtual disk system limitation. Virtual hard disk files must be uncompressed and unencrypted and must not be sparse.'.

Questions:
How to trigger sparse vhd to unclaim space as it was promised in the feature?
How to do manual shink with the sparse vhd if the above does not work?

Answer 1

Hi Kocsis, Szilard Gyorgy,

Please make sure that sparseVhd is set to true in the "[experimental]" section in your .wslconfig file. If the VHD is not newly created, you can set your existing distros to be sparse by running

wsl --manage <distro> --set-sparse <true/false>

https://devblogs.microsoft.com/commandline/windows-subsystem-for-linux-september-2023-update/

Best Regards,

Ian Xue

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