[rhelv6-list] Kernel errors under kvm guest using e1000

[carlopmart]

On 04/20/2011 01:36 PM, John Haxby wrote:
> So you think the virtual ne2k_pci or rtl8139 limit the bandwidth to the
> same as the driver for real hardware? Or, for that matter, that
> virtio_net is limiting the speed to 1GB?
>
> You should find that guest to guest communication through virtual
> interfaces is limited by the performance of the host and guest to
> external machine is limited by the minimum of the raw machine
> performance and the physical NIC.   Is this not the case?
>
> Here I get about 80MB/s between guests (admitedly using xen rather than
> kvm, but the principle is the same) even though the emulated NIC says
> 100Mb/s, which is rather less than the 700Mb/s I'm actually getting.
> (This is not a particularly quick machine either and in fact I'm limited
> by how quckly I'm pulling data off a disk, the maximum attainable speed
> without that is much, much greater).

No, I am not saying that virtual ne2k_pci or rtl8193 limit the 
bandwidth. I have test it.

Using ne2k_pci or rtl8193, bandwidth is 1MB/s-850KB/s, very horrible ... 
Using e1000 driver bandwidth starts at 87-80MB/s at start and after some 
some seconds, bandwidth is degraded until is stalled, for example 
copying a 600MB file using scp ...

But doesn't occurs for example using e1000 driver under vmware 
(workstation or esxi). Bandwidth is stable.

-- 
CL Martinez
carlopmart {at} gmail {d0t} com