Hello everybody!
Watch this video to find out how to install QEMU- KVM hypervisor kernel modules, and add
a virtual machine manager in a Linux operating system.
Also, you’ll see how to create a virtual machine with Windows, and how to recover data
from a KVM virtual machine disk.
KVM (Kernel-based Virtual Machine) is an open-source full virtualization solution for Linux systems.
Just like VirtualBox and VMware Workstation, KVM is a Linux kernel virtualization tool
that turns it into a hypervisor.
Such hypervisor lets users run isolated instances of other operating systems within the host
system.
A virtual machine manager is a piece of software with graphical interface used to control virtual
machines: with this manager, you can operate a virtual machine both locally and over the
network, for example, via SSH protocol.
If there is a reason preventing you from installing VirtualBox or VMware on Linux, you can try
KVM instead.
Within a few minutes, I’ll show you in detail how to add modules that ensure full-scale
KVM operation, with the example of Ubuntu 20.04.
How to check virtualization support Before you begin, it’s necessary to find
out if your computer’s CPU supports KVM and hardware virtualization features.
egrep -c '(vmx|svm)' /proc/cpuinfo If this command returns the result “0”
- your CPU doesn’t support virtualization.
Luckily, everything is OK in my case, so we can continue with the installation.
The next step is to add one more tool to check compatibility: use this command
sudo apt install cpu-checker After that, check if KVM can be used, with
another command sudo kvm-ok
If KVM is supported, the operating system will inform you about your chances to use
KVM acceleration: KVM acceleration can be used
If your hardware is incompatible, you’ll see a notification saying KVM can’t be run.
INFO: Your CPU does not support KVM extensions KVM acceleration can NOT be used
Installing KVM on Ubuntu 20.04 Before installation, update repositories with
the command ‘apt update’ sudo apt update
To add required KVM packages, run the command ‘Install’ with the package names:
sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virtinst virt-manager
-Software ensuring hardware emulation for KVM hypervisor - qemu-kvm.
- Configuration files required to run libvirt as a system service - libvirt-daemon-system.
-Software to manage virtualization platforms - libvirt-clients.
- A set of command prompt tools to configure Ethernet bridges - bridge-utils.
- A set of command prompt tools to create virtual machines - virtinst.
- A graphical interface and command prompt tools required to manage virtual machines
via libvirt - virt-manager.
When asked to agree or disagree, hit Yes, press Enter, and wait until the installation
is complete.
After KVM packages are installed, run the commands to start and enable their booting
with the operating system.
sudo systemctl start libvirtd sudo systemctl enable libvirtd
If the virtual machine manager displays an error message, restart the computer.
How to create a virtual machine in Ubuntu 20.04
Now that the server is configured, let’s run the virtual machine manager with this
command: sudo virt-manager
Or do it with the applications menu by clicking on the program’s shortcut.
In order to create a virtual machine, click on the computer icon in the top left corner.
In the window that opens, choose how to install a virtual machine - with the help of ISO image,
and click “Forward.”
In the next window, specify the path to the previously downloaded ISO image of the operating
system by clicking the Browse button.
Select it, click “Choose volume” and then “Forward.”
After that, specify the amount of system memory and number of processors you’d like to allocate
for this virtual machine, and look at some other settings.
Finally, give the name for this machine, and click “Finish.”
When you do it, the virtual machine will boot automatically, and the installation of the
operating system from the image will begin.
You can visit our channel for a few dedicated video tutorials about installing an operating
system.
How to recover data from a virtual machine As we know, losing data is something inevitable
that every user has to face, sooner or later.
Here is a list of things that typically cause loss of data from a virtual machine:
• Accidentally removed files • Disk formatting
• Failure to mount a virtual file • Damage to index files
• Unexpected power failure • Hypervisor issues, etc
To restore virtual machine files, you need specialized software to find and save the
missing information - and such programs are known as data recovery tools.
For starters, let’s explore where to look for virtual machine files and how to recover
them if the machine cannot be opened: its operating system refuses to boot, or if some
files were accidentally removed or damaged.
To extract virtual machine files from the disk, use Hetman Partition Recovery.
It supports all popular file system formats and can help you restore data after deleting,
formatting, and hardware or software errors.
Connect the hard disk to a Windows computer and start the scan.
You can find KVM virtual machine files by following this path:
Home\lin\.local\share\libvirt\images /var/lib/libvirt\images
The file name corresponds to the virtual machine name, and this is a file with the extension
.qcow2.
Recover it to any available location.
If you have a Linux computer, you can try to access the files even without using specialized
tools.
Upload the virtual machine file into the manager, start the machine, and get the information
you are looking for.
If you failed to boot a virtual machine after system repair operations, or if there is an
error when you try to start it, don’t give up: use our program to open that file and
recover all of its data.
To do it, find the Tools tab - click “Mount Disk”; in the window that opens, you will
choose the disk image type, then check the list for your virtual machine name, or choose
the corresponding file extension, and click “Next.”
Give the path to the folder containing the files by clicking on “Select Folder.”
The program will add all virtual machine files located in that folder: if you need to work
on a specific one, uncheck all other boxes.
To start looking for data, right-click on the disk and choose “Open.”
Then choose analysis type.
Try a “Fast scan” first.
You can see that the program finds all files remaining on the disks without difficulty.
The red cross indicates the ones which have been deleted.
Click on a file to see its contents in the preview window.
To quickly find a specific file, there is a search-by-name feature.
Select the files you need to restore and click “Recovery,” specify the disk where to
save the files and click “Recovery” again.
Conclusion As we all know, virtual machines offer a good
protection against data loss.
However, even with all their advantages, such machines cannot guarantee full protection.
While working with them, you may encounter various issues such as software errors, crashes,
human errors like accidentally removing files or formatting the hard disk and so on.
If you ever lose data from a virtual machine, we recommend using a powerful data recovery
tool, Hetman Partition Recovery.
It supports most virtual disk file formats such as: .vmdk, .vdi, .vhd, .vhdx, .hdd, .hds,
.qcow, qcow2, .img, .cow, .qed.
With a trial version, you can evaluate the program’s effectiveness before actually
paying for the license: you only need the full version to save the files.
That is all for now!
Hopefully, this video was useful.
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Thank you
for watching.
Good luck.