[CentOS-virt] Moving vmware guests to a CentOS KVM server

S.Tindall tindall.satwth at brandxmail.com
Sat Feb 20 02:34:39 UTC 2010

On Sat, 2010-02-20 at 02:41 +0100, Kenni Lund wrote:
> 2010/2/18 compdoc <compdoc at hotrodpc.com>:
> > I would also just use the e1000 emulation. Theres nothing
> > better about the virtio devices...
> ...other than lower CPU utilization and higher throughout? Since these
> are CentOS/RHEL guests, I wouldn't even consider using e1000, I would
> just go for virtio_net.
> I don't have any links, but some time ago there were some benchmarks
> (on the KVM development list?), showing the e1000 maxing out at around
> 300-400mbit/s while the virtio got around 900mbit/s. Even with the
> much higher throughput, the virtio_net driver still had the same or
> lower CPU utilization.
> Do your own testing if in doubt.
> Best Regards
> Kenni Lund

Are you using test-signed drivers or do you have a redistributable
source for release-signed drivers (that chain to a microsoft root)?

Of course, things are much simpler if you are using 32-bit M$ guests.

Never got the chance to test relative performance of e1000 vs the netkvm
drivers on a M$ guest, but on a centos5 guest, virtio absolutely blows
the doors off e1000 performance.

Using ttcp in both directions, typical C5-host-to-C5-guests for e1000
was in the 30-60MB/s range and virtio was in the 300-400MB/s range.


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