Using of qemu-system-x86_64 with key -enable-kvm on VirtualBox
You are trying to use KVM, a hardware assisted hypervisor, inside virtualbox, where this is not supported. What you are trying to do is called nested virtualization, and vbox is a poor choice for such a powerful feature.
Without --enable-kvm
you end up using pure qemu, i.e. emulation and not virtualization, which is terribly slow indeed.
So, really, things are working as expected, you're simply using the wrong tools if you seriously need to use nesting.
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pawan9977
Updated on September 18, 2022Comments
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pawan9977 over 1 year
I have windows 7 as host. I launch virtualbox with ununtu 14.04 on my Windows 7. I try to launch debian inside Ubuntu:
qemu-system-x86_64 -enable-kvm -hda disk.img -boot c -m 256 -localtime
.Another word, there are the following sequence:
Windows 7 -> Ubuntu 14.04 -> Debian
.There is a error, when I use key
-enable-kvm
. Without this key, Mydebian
works very slow. It is launched about 5 minutes. How to fix this trouble? I need the keyenable-kvm
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mikeserv over 9 yearsI'm pretty sure vbox has a checkbox in the system tab (or something like that) for enable nested virtualization,
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dyasny over 9 years@mikeserv virtualbox.org/ticket/4032 no movement and none planned.
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mikeserv over 9 yearsWeird. I must have been thinking about
vmware
. I definitely preferqemu
(or, for linux, just namespace containers) to either and it's been a long time since I installed either. I guess my memory just blended the two together. I do know that a-machine q35
can offer a bit of a speed increase for a pureqemu
hvm, though. -
pawan9977 over 9 years@dyasny, yep, you are absolutely right. I understand this theory. But I think, that there is some way to solve my problem. It seems, that I have to choose vmware...
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dyasny over 9 yearsJust make sure whatever you choose supports nesting. Your hardware should also support it (IOMMU support)