virtualbox.org

The error can be seen from the screen copy.

Provide a VM log file. Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

Please find the attached log file. Thanks

I suggest that you give the VM a second CPU core, and increase graphics RAM to 128MB.

But I believe your main problem is caused by having Hyper-v enabled.

00:00:01.947571 HM: HMR3Init: Attempting fall back to NEM: AMD-V is not available
00:00:01.960462 NEM: info: Found optional import WinHvPlatform.dll!WHvQueryGpaRangeDirtyBitmap.
00:00:01.960498 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

I tried to increase the Video mem to 128MB， and added one extra core, but it's still not working. I tried to not use Hyper-V, and use the KVM, it now can start the OL7 Linux. Thanks for pointing me to the direction.

Fujitsu_user wrote:I tried to not use Hyper-V, and use the KVM

I think you should read the FAQ I linked you to. It tells you precisely what to do.

The hypervisor API VM setting (where you state whether the guest OS running in the VM can use a Hyper-v or KVM API) has nothing to do with the hypervisor mode physical host the hardware uses. And it is the latter which conflicts with the VM.

In my previous post I highlighted a line in the log file. If that line is still present then the problem is not solved. Failure to solve it will no doubt cause you to continue to have strange crashes and poor performance.