Re: Poor network performance with cable modem assigned to guest

[Jon Fairbairn <jon.fairbairn@cl.cam.ac.uk>]

Brian Jackson <iggy@theiggy.com> writes:

> On Friday 28 August 2009 01:14:42 pm Jon Fairbairn wrote:
>> I'm experimenting with a virtual router. I did this a few years ago with
>> Xen and it worked well enough, but then fedora changed and it stopped
>> working, so I gave up for a while. Now I have a machine that supports
>> hardware virtualisation, I thought I'd try again.
>>
>> The setup was done through virt-manager. The network between the host
>> and guest is a virtual bridge. What I've been trying to do is to assign
>> a USB cable modem to the guest,
>
>
> This is probably your problem here. KVM only emulates a usb1.1
> controller,

that shouldn't be a problem as the cable modem is only a usb 1.1 device.

> and from all reports, it doesn't really do that very well.

Not very well? We're talking about a factor of *FIFTY* slow down here.
If I'd implemented the driver in a 1980s lazy functional language I
would have only expected a factor of ten :-P ;-).

> There have been numerous reports of poor performance even for a usb1.1
> device. You should check the archives to see if there was ever any
> kind of tips or resolution to some of those problems.

I had a look, but I couldn't find anything helpful. Maybe I'm searching
for the wrong things?

-- 
Jón Fairbairn                                 Jon.Fairbairn@cl.cam.ac.uk