Starting my laptop today, I noticed that in my Task Manager, the "Default Switch" adapter has disappeared from the network adapters. Then I noticed that I can't ssh to the Hyper-V VM I setup few days earlier. This quite puzzled me because as turns out the ArchWSL I setup with WSL2 also failed to start, and this error flooded my event viewer. As a side note, the VM starts fine, but it doesn't have any network at all.
Tried to delete Hyper-V feature and reinstalling it back, issue still persist. sfc /scannow, "Windows protection did not find any integrity violations". So one best guess is that somehow removing Hyper-V doesn't remove all the network switches configuration. Time to do something dangerous.
Strong Notice: Steps below is dangerous to do. Consider creating system restore point prior performing steps I mentioned below. You'll also lose all your Hyper-V VMs (and all Virtual Switch configurations) so ensure you have exported your VM beforehand.
- Be prepared for lots of reboots.
- Uninstall Hyper-V and all its related components. In optionalfeatures.exe, untick Hyper-V, Virtual Machine Platform, and Windows Hypervisor Platform. Unticking Windows Subsystem for Linux is not needed (despite using Hyper-V for WSL2). Then, click reboot.
- Open regedit.exe, then navigate to HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vmsmp\parameters\SwitchList and delete all subkeys there. Same goes to NicList above SwitchList, remove all subkeys.
- Reboot
- Repeat step 3 until there are no more subkeys.
- If you deleted some values in step 5, reboot.
- Go to C:\ProgramData\Microsoft\Windows\Hyper-V, you may need to take the ownership of that folder, don't worry. Windows Explorer will ask you to do so in 1 click of a button.
- Delete everything in that folder.
- Reboot
- Repeat step 3 and 5 again
- Do the reverse of step 2, including the reboots.
- After the system boots up for a while, open elevated powershell and command prompt. In the elevated powershell, type "Get-VMSwitch". This one should hang, don't worry. Then in the elevated command prompt, execute "sc start hns".
- Wait for a moment, then you should see "Default Switch" back in Task Manager. And the elevated powershell window should return values (no longer hangs).
- Reconfigure your network switch if needed
- Import back your VMs.
I don't quite remember the steps but that's what I've been done. Now WSL2 starts again and I cna ssh back to the VMs after I imported it.
What a blog post to start 2021
 |
| https://knowyourmeme.com/photos/1918696-disappointed-black-guy |
... unless it shows 34 December 2020 instead
