My question is regarding the possibility of an particular thing. I have Debian installed on my system and have win 8 as an virtual os using virtual box
Is it possible to bypass linux completely or partially and boot directly into the Win 8 virtual OS? maybe creating an entry into grub or something like that
I'm pretty sure that we can not do that, because the virtual box itself is installed on the Debian so we need the Debian to start the virtual box and then the virtual OS.
No, you cannot. The best you can get to is converting the Virtualbox .vdi to a partition, but even then it isn't likely to boot. See this answer.
I was looking for doing the same thing I found couple good guides on the web
https://www.maketecheasier.com/log-into-a-virtualbox-session-in-ubuntu/
https://askubuntu.com/questions/404665/how-to-start-virtual-box-machines-automatically-when-booting
Related
I have to submit a C++ project for marking soon, and I call system("cls") to clear the console a few times in my code. I know there are better methods but I just went for the easiest option.
As far as I am aware, system("cls") only works in Windows. The person who is going to mark my code will be using a virtual Windows machine in a computer with Mac. I have never used a virtual machine and I don't know much about them so I just want to make sure my code will run fine.
Yes it will. A Windows VM contains a regular Windows installation, running on a virtualised processor (under the control of the 'hypervisor').
i have several virtual machines running on virtual box on my main Ubuntu OS.
But after the security updates (Spectre and Meltdown) on windows they weirdly stopped working.
I tried looking up the problem on google but it seems like no one else has experienced this problem.
Side Notes:
I have 2 OS-Systems (Windows/Ubuntu) running on a dual boot.
I have VT-X/AMD-v enabled in my BIOS settings and i disabled Hyper-V
on my Windows machine
I dont know how those two OS-Systems are even connect but i noticed
that my time switches about a hour if i first start Ubuntu and then
Windows. Therefore i guess that they are linked in some way
Some of the Virtual Machines require VT-X/AMD-v. I tried starting
those who dont require VT-X/AMD-v without it and they worked fine.
All machines worked perfectly fine before
Not sure if this question is off-topic on this website. If it is i'd be happy if someone can link me to places where this question is suitable.
What you experience is most likely a bug in the Virtualbox. Submit an issue to their bug tracker.
I have VT-X/AMD-v enabled in my BIOS settings and i disabled Hyper-V on my Windows machine
This is fine and is actually required.
my time switches about a hour if i first start Ubuntu and then Windows.
Most likely the timezone settings are different in two OSes, or one OS assumes that the CMOS clock runs in UTC and another thinks it is in local time zone. It has nothing to do with your problem.
Some of the Virtual Machines require VT-X/AMD-v.
Apparently pure application level software works fine, but hardware-accelerated VMMs require kernel modules to be loaded, and those may need adjustments after kernel updates, especially so drastic ones.
Not sure if this question is off-topic on this website.
Yes, it looks like this question is more suitable for ServerFault https://serverfault.com/
I am trying to find a way to programatically detect that my program runs on a virtual machine, as far as I know there is no common way for parallels to do that.
Windows 8 task manager performance tab displays a "Virtaulization" option, what does it mean? When i run windows 8 in a virtual machine it changes to virtual processors and virtual machine: yes, so some how windows 8 detects that it is running inside a virtual machine, how does windows 8 detect that it is running in a virtual machine? Is it possible to get this information programatically? I tried both on parallels and vm ware and both works fine.
You should take a look at this interesting article Red Pill... or how to detect VMM using (almost) one CPU instruction by Joanna Rutkowska which used to be here but is now dead and can only be viewed with the waybackmachine here and Virtualization: Red Pill or Blue? by Steven McElwee which also used to be here but can now only be viewed here.
Heres the code:
int swallow_redpill()
{
unsigned char m[2+4], rpill[] = "\x0f\x01\x0d\x00\x00\x00\x00\xc3";
*((unsigned*)&rpill[3]) = (unsigned)m;
((void(*)())&rpill)();
return (m[5]>0xd0) ? 1 : 0;
}
It should return 1 if running in a virtual machine and 0 if not.
Edit: It may return false-positives on modern cpus and its apparently better to combine a couple of tests together to make sure the result is real.
On VMware you could check for the CD drive vendor- should be "VMware" or "VMware, Inc." or something like this.
I don't know about VMware workstation but on ESXi your MAC address generally starts with "00:50:56". You could make use of this, too.
Have a look at virt-what. Maybe you can port it to Windows.
And maybe How to detect install is running on a VM? can help you.
i wrote a cuda program and i am testing it on ubuntu as a virtual machine. the reason for this is i have windows 7, i don't want to install ubuntu as a secondary operating system, and i need to use a linux operating system for testing.
my question is: will the virtual machine limit the gpu resources? So will my cuda code be faster if i run it under my primary operating system than running it on a virtual machine?
I faced a similar task once. What I ended up doing was installing Ubuntu on a 8GB thumb drive with persistent mode enabled.
That gave me 4GB to install CUDA and everything else I needed.
Having a bootable USB stick around can be very useful. I recommend reading this.
Also, this link has some very interesting material if you're looking for other distros.
Unfortunately the virtual machine simulates a graphics device and as such you won't have access to the real GPU. This is because of the way the virtualisation handles multiple VMs accessing the same device - it provides a layer in between to share the real device.
It is possible to get true access to the hardware, but only if you have the right combination of software and hardware, see the SLI Multi-OS site for details.
So you're probably out of luck with the virtualisation route - if you really can't run your app in Windows then you're limited to the following:
Unrealistic: Install Linux instead
Unrealistic: Install Linux alongside (not an option)
Boot into a live CD, you could prepare a disk image with CUDA and mount the image each time
Setup (or beg/borrow) a separate box with Linux and access it remotely
I just heard a talk at NVIDIA's GPU technology conference by a researcher named Xiaohui Cui (Oak Ridge National Laboratory). Among other things, he described accessing GPUs from Virtual machines using something called gVirtuS. He did not create gVirtuS, but described it as an opensource "virtual cuda" driver. See following link:
http://osl.uniparthenope.it/projects/gvirtus/
I have not tried gVirtuS, but sounds like it might do what you want.
As of CUDA 3.1 it's virtualization capabilities are not vivid, so the only usable approach is to run CUDA programs directly on the target HW+SW
Use rCUDA to add a virtual GPU to your VM.
I've been hearing a lot about about how the new version of VMWare Fusion can run virtual operating systems in "headless mode".
A Google search makes it clear that other virtualisation products also have similar features, however, I have not been able to find a good description of what this actually means? What is happening when you do this?
Headless mode means that the virtual machine is running in the background without any foreground elements visible (like the Vmware Fusion application)
You would have no screen to see running the front end; i.e. the screen/console would not be visible, even though the operating system is running, and would typically have to access the machine via SSH.
For anyone that is interested, you can activate headless mode in VMWare Fusion by running the following command in Terminal.app
defaults write com.vmware.fusion fluxCapacitor -bool YES