I was configuring *kvm* on my laptop which has **ubuntu 14.04** as the host OS. I added a **Fedora guest OS** using the *virt-manager* and it worked fine.

However, after I rebooted the virtual machine, the guest OS is not coming up. It gives me an error as,

 Booting from hard disk
 Boot failed: not a bootable disk
 No bootable device

When I searched for this error, the solutions suggested changing the **xml** configuration file of my guest OS. I tried changing the **xml** configuration file using the command `virsh edit ramesh-guest` but no luck. 

This is my **xml** configuration file. 

 <disk type='file' device='disk'>
 <driver name='qemu' type='raw'/>
 <source file='/var/lib/libvirt/images/ramesh-guest.img'/>
 <target dev='hda' bus='virtio'/>

I also tried changing the storage type as suggested [here](http://azitech.wordpress.com/2011/07/23/no-bootable-device-on-kvmqemu/) but to no luck.