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pongthorn.datastax asked Erick Ramirez commented

Cannot start DS201 VM, getting VERR_NEM_NOT_AVAILABLE and VERR_VMX_NO_VMX errors


I have been training in DS201 in Academy . I cannot start DS201-VM-6.0.ova in Oracle Virtualbox.

My environment and software setup is listed below

  1. OS=Window server 2019 standard (64bit)
  2. Ram 8 GB
  3. VM Oracle : VirtualBox-6.1.16-140961-Win.exe
  4. File:DS201-VM-6.0.ova

I attempted to follow as this document link below.


I got stuck in step 4 as the figure shown in below.


I am suspicious that DS201-VM-6.0.ova incompletely downloaded, Yet I try to download 2 times. both files still cannot import to start alike.

is it a corrupt file problem?



Thank you for your advice.

John Eq

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1 Answer

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Erick Ramirez answered Erick Ramirez commented


You can validate your downloaded version of the DS201 VM image by performing an MD5 checksum on the file using the Windows CertUtil utility.

Here's an example hash output to compare to:

C:\Users\erick\Downloads>CertUtil -hashfile DS201-VM-6.0.ova MD5
MD5 hash of DS201-VM-6.0.ova:
CertUtil: -hashfile command completed successfully.

Depending on the kind of CPU and disk installed on your Windows machine, this can take several minutes to complete.


However, I don't think the problem is with the VM image itself. The errors VERR_NEM_NOT_AVAILABLE and VERR_VMX_NO_VMX indicate a configuration problem with your Windows machine and VirtualBox.

In my experience the most common cause of this problem is a Windows 10 service that uses Microsoft Hyper-V on your Windows machine that is blocking VirtualBox.


You will need to disable Hyper-V on your Windows machine to get VirtualBox to work.

Since this isn't a DataStax software issue, I recommend you search the VirtualBox forums ( for both VERR_NEM_NOT_AVAILABLE and VERR_VMX_NO_VMX to get details on the issue and how to disable Hyper-V on Windows. Cheers!

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I try to do the following step to fix as your advice

1. performed an MD5 checksum on the file using the Windows CertUtil utility.

2.Disable Hyper-V

But I still can't start VM. But the error message has changed from the first one like the above question. This is the current error.

I try to fix according to troubleshooting a user manual it advises doing workaround as here

I did all of them, but it still has an error

- Turn Intel VT-x On in Bios

-Try Uninstalling Hyper-V

I have no idea about fixing this problem.

this is my system info.

is it possible to install in my own environment, but my environment is Window 10 Enterprise

Thank you

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Unfortunately, this is a problem with your PC/laptop so I can't troubleshoot it for you.

I use a Macbook Pro for work but I am able to import the VM and run it on a Microsoft Surface Laptop 3 and a Microsoft Surface Pro 7 so I know it definitely works on Windows 10.

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