Installation guide

vi rti o_net and vi rti o _bl k are the only drivers whose order can be changed. If other drivers are
loaded in a different order, they will not work.
Next, configure the modules. Locate the following section of the /etc/rc. d /rc. sysi ni t file.
if [ -f /etc/rc.modules ]; then
/etc/rc.modules
fi
Append the following lines after that section:
if [ -f /etc/rc.modules ]; then
/etc/rc.modules
fi
modprobe virtio
modprobe virtio_ring # Comment this out if you do not need block driver
modprobe virtio_blk # Comment this out if you do not need block driver
modprobe virtio_net # Comment this out if you do not need net driver
modprobe virtio_pci
Reboot the guest virtual machine to load the kernel modules.
Ad d in g t he virt io d rivers t o t h e in it rd RAM d isk
This procedure covers loading the virtio driver modules with the kernel on a Red Hat Enterprise Linux
3.9 or newer guest by including the modules in the initrd RAM disk. The mkinitrd tool configures the
initrd RAM disk to load the modules. Specify the additional modules with the --with parameter for
the mki ni trd command. Append following set of parameters, in the exact order, when using the
mki ni trd command to create a custom initrd RAM disk:
--with virtio --with virtio_ring --with virtio_blk --with virtio_net --
with virtio_pci
AMD6 4 an d In t el 6 4 issu es
Use the x86 _6 4 version of the virtio package for AMD64 systems.
Use the i a32e version of the virtio package for Intel 64 systems. Using the x86 _6 4 version of the
virtio may cause a 'Unreso l ved symbo l ' error during the boot sequence on Intel 64 systems.
Net wo rk p erf o rman ce issues
If you experience low performance with the virtio network drivers, verify the setting for the GSO and
TSO features on the host system. The virtio network drivers require that the GSO and TSO options
are disabled for optimal performance.
Verify the status of the GSO and TSO settings, use the command on the host (replacing interface with
the network interface used by the guest):
# ethtool -k interface
Disable the GSO and TSO options with the following commands on the host:
Red Hat Ent erp rise Linux 6 Virt ualiz at ion Host Configurat ion and G uest Inst allat ion G uide
84