CentOS Dedicated Server: Setting Up KVM Virtualization

September 2015

Install KVM on CentOS

Kernel based virtual machines, commonly known as KVM virtualization, are arguably one of the powerful and stable virtualization technologies. KVM builds on the power of hardware-based virtualization to deliver outstanding performance.

KVM virtualization is a popular choice because it does not support overselling natively. Coupled with our SSD servers, KVM virtualization will deliver a truly amazing experience for your clients. This article will outline how to install KVM on CentOS 6.

KVM virtualization

Linux-based KVM virtualization logo via OpenVirtualizationAlliance.org

KVM Hardware Requirements

To install KVM on CentOS, you need your dedicated server to support hardware virtualization. This is called Intel VT  for Intel based CPU’s (specifically Intel Xeon’s), and AMD-V for AMD processors (specifically AMD Opteron’s).

How to Install KVM on CentOS Dedicated Server

Step 1: Install required packages

yum -y install @virt* dejavu-lgc-* xorg-x11-xauth tigervnc \ libguestfs-tools policycoreutils-python bridge-utils

Step 2: Set Sellinux context

semanage fcontext -a -t virt_image_t “/vm(/.*)?”; restorecon -R /vm

Step 3: Allow packet forwarding

sed -i ‘s/^\(net.ipv4.ip_forward =\).*/\1 1/’ /etc/sysctl.conf; sysctl -p

Step 4:  Configure libvirtd

chkconfig libvirtd on; shutdown -r now

Host Setup is now complete! Time to setup the virtual containers.

Step 1: View available OS templates

virt-install –os-variant=list | more

Step 2: Select an OS variant



OS=”–os-variant=win7 –disk path=/var/lib/libvirt/iso/virtio-win.iso,device=cdrom”


OS=”–os-variant=win2k8 –disk path=/var/lib/libvirt/iso/virtio-win.iso,device=cdrom”


Step 3: Select a network option

Net=”–network bridge=br0″ Net=”–network model=virtio,bridge=br0″

Net=”–network model=virtio,mac=52:54:00:00:00:00″

Net=”–network model=virtio,bridge=br0,mac=52:54:00:00:00:00″

Step 4: Select a disk option

Disk=”–disk /vm/Name.img,size=8″

Disk=”–disk /var/lib/libvirt/images/Name.img,size=8″

Disk=”–disk /var/lib/libvirt/images/Name.img,sparse=false,size=8″

Disk=”–disk /var/lib/libvirt/images/Name.qcow2,sparse=false,bus=virtio,size=8″ Disk=”–disk vol=pool/volume” Disk=”–livecd –nodisks”

Disk=”–disk /dev/mapper/vg_…”

Step 5: Select a source



Src=”-l http://alt.fedoraproject.org/pub/fedora/linux/releases/20/Fedora/x86_64/os/” Src=”-l http://download.fedoraproject.org/pub/fedora/linux/releases/20/Fedora/x86_64/os/”

Src=”-l http://ftp.us.debian.org/debian/dists/stable/main/installer-amd64/ Src=”-l http://ftp.ubuntu.com/ubuntu/dists/trusty/main/installer-amd64/”

Src=”-l http://download.opensuse.org/distribution/openSUSE-stable/repo/oss/” Src=”–location=http://mirror.centos.org/centos/6/os/x86_64″

Step 6: Select Number of CPU’s




Step 7: Select amount of ram

Ram=”–ram=768″ Ram=”–ram=1024″ Ram=”–ram=2048″

Step 8: Choose a name for the guest


Step 9: Create the guest

virt-install $OS $Net $KS $Disk $Src $Gr $Cpu $Ram –name=$Name

Step 10: Connect to the console

virt-viewer –connect qemu_ssh://myvps/$Name

Step 11: You can set this VPS to boot on server startup

virsh autostart $Name


That’s it! Your CentOS dedicated server is now configured with KVM virtualization.

Contact our support team for questions on how to install KVM, or on choosing the perfect dedicated server for your KVM hosting needs.

Liked this post? Read more articles on System Administration or Dedicated Server Hardware.