Support Tips: Scale HC3 VirtIO Performance Drivers
blakerodier last edited by blakerodier
Hey all. Another tip from support. This time we wanted to talk about performance drivers.
HC3 uses the KVM hypervisor which can provide para-virtualized devices to the guest OS which will decrease latency and improve performance for the virtual devices. Virtio is the standard used by KVM. We recommend selecting performance drivers for any supported OS which creates Virtio block devices. Emulated block devices are also supported for legacy operating systems.
Virtio driver support has been built into the Linux Kernel since 2.6.25. Any Linux distro utilizing a 2.6.25 or later distro will natively support Virtio network and storage block devices presented by HC3. Older kernels can potentially allow the Virtio modules to be backported. Any modern Linux distro should be on a Kernel version late enough to natively support Virtio.
Virtio drivers for Windows OSs are available for guest and server platforms starting at Windows XP and Windows Server 2003. There are Virtio drivers available for all OS releases since those releases. Any OS older than XP or Server 2003 will have to use the emulated non-performance block device type and will experience decreased performance compared to more modern OSs.
At Scale Computing, we periodically update the Virtio performance drivers provided with HC3 via firmware updates. We recommend only using the included Virtio ISO or one provided by Scale Support. Untested Virtio drivers could cause an inability to livemigrate VMs or other issues. New Virtio drivers will not be automatically added to guest VMs. You will need to mount the ISO CD to the VM and manually install the updated drivers via device manager. You can also utilize group policy to roll out updates of virtio drivers when they are available, which we will have an application note outlining that process soon.