These hardware is exactly the same, no changes in bios, reinstalled from scratch.

The versions in the "old ones" are:

RHEL 5.6

kvm-83-224.el5

libvirt-0.8.2-15.el5_6.1

kmod-kvm-83-224.el5

kvm-tools-83-224.el5

libvirt-0.8.2-15.el5_6.1

Kernel: 2.6.18-238.1.1.el5 #1 SMP Tue Jan 4 13:32:19 EST 2011 x86_64 x86_64 x86_64 GNU/Linux

I the ovirt "new" ones:

RHEL 6.5

qemu-img-rhev-0.12.1.2-2.415.el6_5.14.x86_64

qemu-kvm-rhev-0.12.1.2-2.415.el6_5.14.x86_64

qemu-kvm-rhev-tools-0.12.1.2-2.415.el6_5.14.x86_64

libvirt-0.10.2-29.el6_5.12.x86_64

libvirt-client-0.10.2-29.el6_5.12.x86_64

Kernel: 2.6.32-431.23.3.el6.x86_64 #1 SMP Wed Jul 16 06:12:23 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux

I haven't gone into the details but the command line generated by our old software is like 2 lines of text while in the ovirt nodes for the same type of machine it is 10 :)