Tuesday, May 20, 2014

How to fix the garbled font on virt-manager on rhel7 (currently beta)?

I was trying to do some tests with nested virtualization. For convenience, I decided to use virt-manager inside a vm to manage vms that I am going to run on top of that vm. (That is what nested virtualization means). I did "yum install virt-manager" and launched virt-manager. I could see the font is completely garbled.

After a bit research (or search), I found the simple resolutoin. Just install dejavu-sans-fonts package.

# yum install dejavu-sans-fonts

How do I enable nested virtualization on KVM?

Nested virtualization allows you to run virtual machines inside a virtual machine. Though this is not good for any kind of production use case because of the performance issues involved, this is usually good for testing purposes. Eg, students can be given virtual machines to test virtualization without allocating physical systems per head count.

I am only covering intel cpus in this blog post. The steps are very simple.

  • Verify that nested virtualization is not enabled already.
cat  /sys/module/kvm_intel/parameters/nested
  •  Add below line to /etc/modprobe.d/kvm-intel.conf
options kvm-intel nested=1
  • Reboot the host or do
modprobe -r kvm-intel
modprobe kvm-intel
  • Verify that nested virtualization is enabled.
cat  /sys/module/kvm_intel/parameters/nested