It’s a lightweight Hyper-V VM, just like Windows itself when you turn Hyper-V support on (boots hypervisor first, then the Windows VM in the root or parent partition)[0].
But if that’s an issue, WSL1 is still an option.[1] It’s a thin translation layer between Linux kernel calls and NT kernel calls, which was the original concept of subsystem from the early NT days which allowed OS/2 apps to run on top of ntdll.dll.
It’s not an issue, in fact as a Linux fan it’s magnificent! However it is not windows so if you want to use it for windows stuff / software development there’s going to be some edge cases, performance penalties and hiccups. So long as you stay inside the WSL2 VM and filesystem it’s fantastic.
Also WSL1 was a subsystem in the NT kernel but WSL2 is not like this - it runs a separate Linux kernel, with some
convenient integrations. WSL1 never did support all the features - I recall I had to use windows .exe executables for some software packages that do have apt-installable packages.
It kind of did, IMO. You can still use WSL1, but my understanding is that it's a dead end; MS has given up on the translation layer approach. WSL1 will still get bugfixes but it seems pretty clear that WSL2 will get the lion's share of investment going forward.
But if that’s an issue, WSL1 is still an option.[1] It’s a thin translation layer between Linux kernel calls and NT kernel calls, which was the original concept of subsystem from the early NT days which allowed OS/2 apps to run on top of ntdll.dll.
WSL2 didn’t replace WSL1.
[0] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-...
[1] https://learn.microsoft.com/en-us/windows/wsl/compare-versio...