Virtio HDs and NICs

[Cybodog]

When making KVMs there is a Virtio option for both HDs and NICs.

I am slightly aware of the KVM efforts to develop virtio devices.

1.What is your recommended device for a HD if the KVM is Linux and the recommended device for a NIC?

2. Same if question only running Windows.

 

[tom]

When making KVMs there is a Virtio option for both HDs and NICs.

I am slightly aware of the KVM efforts to develop virtio devices.

1.What is your recommended device for a HD if the KVM is Linux and the recommended device for a NIC?

modern Linux Kernels include virtio block and network drivers and this is the preferred way.

2. Same if question only running Windows.

for network, e1000 (with drivers from intel website) and IDE for disks. there are new virtio block and net driver in development and also in beta but not available for public. due to the fact that redhat 5.4 will include official support for windows KVM guests I expect theses drivers will be release together with redhat 5.4 - but I do not know under which license.

 

[Cybodog]

Thank you for the complete answer!

 

[mangoo]

modern Linux Kernels include virtio block and network drivers and this is the preferred way.

With vanilla KVM, yes.

But Proxmox patches to KVM (fairsched patch to be exact) currently break guests running virtio_net (and guests become slow after some time).

So from experience, I'd recommend running e1000, until at least it's possible not to use fairsched/cpuunits for KVM guests.

 

[thegmin]

I have a little question / don't want to start a whole new topic on it /. Today me and some frineds are starting a Counter Strike server , but I am not sure what type of virtual NIC to use. The guest os will be Windows XP SP3.

 

[tom]

I have a little question / don't want to start a whole new topic on it /. Today me and some frineds are starting a Counter Strike server , but I am not sure what type of virtual NIC to use. The guest os will be Windows XP SP3.

use e1000 with latest drivers from www.intel.com.

 

[thegmin]

use e1000 with latest drivers from www.intel.com.

thx

 

[nixgeek]

if one creates a KVM for Linux guest using IDE can it be switched to virtio disk later?

 

[fromport]

if one creates a KVM for Linux guest using IDE can it be switched to virtio disk later?

Sure, you will have to edit grub/lilo & fstab accordingly on the guest.
Shutdown the guest, on the host edit the corresponding file in /etc/qemu-server/103.conf (sample conf file obviously) and exchange

bootdisk: ide0
ide0: vm-103-disk.qcow2

to

bootdisk: virtio0
virtio0: vm-103-disk.qcow2

And start your guest.

Of course the linux guest must have all the virtio drivers available ...

 

[garrettwp]

With vanilla KVM, yes.

But Proxmox patches to KVM (fairsched patch to be exact) currently break guests running virtio_net (and guests become slow after some time).

So from experience, I'd recommend running e1000, until at least it's possible not to use fairsched/cpuunits for KVM guests.

Is this still the case with using virtio_net under linux? My kvm's are using both virtio for disk and network. They are running Ubuntu as the OS. I have not seen any issues in the last few days. I am curious to know if using virtio_net will still cause issues.

- Garrett