Page 1 of 2

This kernel requires x86-64 cpu, but only detected i686 cpu

PostPosted: 26. Feb 2015, 18:09
by Harian
After much initial difficulty I finally managed to install Kali Linux 64 Bit ISO into Virtual Box and made it to the Boot Up menu but whenever I selected an installation option it kept saying it required an x86-64 CPU and I'm not sure how to enable this. I noticed under System Settings that I was unable to access the Acceleration tab; and that I couldn't adjust the Processor(s) beyond 1 under the Processor tab.

I've been trying to teach myself digital forensics you see and so really need this particular Linux distribution to work on my Windows 7 PC. Does anyone here know how to work Kali Linux on Virtual Box and specifically what to do about this requirement of an x86-64 CPU when only an i686 CPU is detected?

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 26. Feb 2015, 18:19
by Perryg
1) 64-bit guests need hardware-virtualzation enabled in the hosts bios.
2) when creating the 64-bit guest you must select 64-bit in General -> Basic -> version.
3) If running Windows as host you must make sure hyper-v or xp mode is not enabled on the host. MS does not play well and wants it all.

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 28. Feb 2015, 09:31
by c99a
I have the same issue.
Only wondering: why does vmware work flawlessly and virtualbox can't install 64 bit OS ?

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 28. Feb 2015, 09:38
by loukingjr
c99a wrote:I have the same issue.
Only wondering: why does vmware work flawlessly and virtualbox can't install 64 bit OS ?

VirtualBox can install 64bit guests. I have 24 of them. Being able to read helps. See Perryg's post just above yours.

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 28. Feb 2015, 10:41
by c99a
loukingjr wrote:
c99a wrote:I have the same issue.
Only wondering: why does vmware work flawlessly and virtualbox can't install 64 bit OS ?

VirtualBox can install 64bit guests. I have 24 of them. Being able to read helps. See Perryg's post just above yours.


Oh I can read allright. Seems that you can't comprehend. Virtualbox on my machine cannot translate the CPU's virtualization instructions for 64 bit guests. Vmware could do that.

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 28. Feb 2015, 11:33
by mpack
VirtualBox can run 64bit guests just fine, under the same conditions as VMWare. No translation or simulation is involved: in a VM the guest code runs natively on the host processor. So, all that really matters is the host CPU capability. Just make sure you don't try to run both VM platforms at the same time (including nested).

FAQ: I have a 64bit host, but can't install 64bit guests.

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 28. Feb 2015, 12:27
by c99a
mpack wrote:VirtualBox can run 64bit guests just fine, under the same conditions as VMWare. No translation or simulation is involved: in a VM the guest code runs natively on the host processor. So, all that really matters is the host CPU capability. Just make sure you don't try to run both VM platforms at the same time (including nested).

FAQ: I have a 64bit host, but can't install 64bit guests.

I've attached my cpu specs and virtualbox create new virtual machine window. See how it's only for 32bit. That was before I tried to test vmware, so no other virtualization software running.
I currently am on windows 8 64 bit.

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 28. Feb 2015, 12:31
by mpack
I again refer you to the FAQ. Go through it systematically. I wrote the FAQ because I got tired of this conversation quite some time ago!

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 3. Mar 2015, 22:52
by jeebc
I had this issue as well today (not only today) and finally this did the trick :

Set the "Version" and "Type" properties to "Other" and "Other/64 bit" (similar to that anyway)
It was set to Linux (which matched the client OS), and only after that change if finally worked.

The option was already set to allow virtualisation on this machine, but on a lot of machines that seems to be an issue indeed.

Re: This kernel requires x86-64 cpu, but only detected i686

PostPosted: 23. Aug 2016, 17:16
by xelalao
jeebc wrote:I had this issue as well today (not only today) and finally this did the trick :

Set the "Version" and "Type" properties to "Other" and "Other/64 bit" (similar to that anyway)
It was set to Linux (which matched the client OS), and only after that change if finally worked.

The option was already set to allow virtualisation on this machine, but on a lot of machines that seems to be an issue indeed.



Excellent... your info save me a lot of time! THANKS a lot!

Re: This kernel requires x86-64 cpu, but only detected i686 cpu

PostPosted: 25. Dec 2016, 01:45
by khramahy
Hi, I have experienced the same message, and I have noticed the VM installed under General tab: Red Hat 32. I removed the VM and re-created it using the same process and it worked. I have Lenovo Thinkpad T440p, the only difference between the two tries was that I initially did the import prior to modifying the device BIOS to support VM functionality. I changed the BIOS later but had that error.

Hope this helps.

Re: This kernel requires x86-64 cpu, but only detected i686 cpu

PostPosted: 13. Jan 2017, 17:10
by Shadab-takhar
It is very simple. You need to enable virtualiziation in Bios setup. Just reboot your computer and goto Bios setup and in system find virtualization and enable it. Then save and exit. And you will be able to install your desired OS.

Re: This kernel requires x86-64 cpu, but only detected i686 cpu

PostPosted: 13. Jan 2017, 17:57
by mpack
The message comes from the Linux Guest, not from VirtualBox, but it means that you tried to install a 64bit Linux guest into a 32bit VM.

The most likely reason you chose a 32bit profile in VirtualBox is because you didn't see any 64bit profiles, and that would be because VT-x is unavailable for any of the reasons mentioned in the FAQ.

Re: This kernel requires x86-64 cpu, but only detected i686 cpu

PostPosted: 13. Jan 2017, 18:59
by BelJoost
If you have VT-x enabled in BIOS, yet no 64bit for guest hosts, do read that thread. It's about two other bios settings: Execute Disable and Trusted Execution. Which are not (yet) mentioned in the faq by mpack.

Re: This kernel requires x86-64 cpu, but only detected i686 cpu

PostPosted: 13. Jan 2017, 19:38
by socratis
BelJoost wrote:Which are not (yet) mentioned in the faq by mpack.

Maybe because they're not actually required? In fact, I was running VirtualBox on my Win7 other host and I hadn't enabled the NX-bit by ignorance/accident. There was no problem running 64-bit guests. None.

What most probably happened in the thread you're linking is that the user shut down the host completely and restarted it. This is required for such "invasive" changes and the OP didn't actually do it when they had VT-x switched to enabled.