Hello
Thank you for your question and reaching out. I can understand you are having query\issues related to Hyper-V VM
It may happen if you have VM with Dynamic Disk allocation
Please try to shrink the VM size and to the lowest possible or Export the VM to different location having enough disk size.
It might be that you have used more disk space at some point, and now you only use about 170GB of disk space, dynamically expanding virtual disks (VHD/VHDX) will grow as needed, but they will not release any space even if you delete data from the disk.
If you want to reduce the upper size limit of your VHDX you would need to shrink the VHDX disk.
To shrink a VHDX you can use the Resize-VHD PowerShell cmdlet.
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