I have a Windows 10 as main OS and VirtualBox Ubuntu 20.04 virtual machine in it. PC has only one internal hard drive. I’m not satisfied the virtual machine perfomance, so I’m looking for the way to install this particalar Ubuntu (as I have all working environment there) as 2nd OS, so I could switch between both of them. Is there any way I can do that?
See the last entry in this thread for advice.
I cannot vouch for it but it will give you more info on what to search for to solve this problem.
On the other hand I would suggest looking at your VBOX performance for a moment before you do “Open Kernel Surgery”.
Raise the Memory allocation to the VM.
Add a CPU.
Move the Virtual disk to an SSD if you have one.
If not on a SSD the test the fragmentation on the HD and defrag if needed.
One the HD is defrag consider converting the dynamic disk to a fixed disk.
This should be more effective on a spinning disk than SSD.
See https://maxrohde.com/2014/06/21/convert-dynamically-sized-virtualbox-vdi-hard-drive-to-fixed-size/ for some guidance.
Boost the Video memory allocation to the VM.