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Re: [Xen-users] Does Xen 3.3 support giga bit network in the guest?

To: "Fajar A. Nugraha" <fajar@xxxxxxxxx>
Subject: Re: [Xen-users] Does Xen 3.3 support giga bit network in the guest?
From: Abdul Qadeer <qadeer.qadeer@xxxxxxxxx>
Date: Thu, 12 Feb 2009 21:50:07 +0500
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Since you want to use Xen 3.3 anyway, instead of changing the emulated
NIC type I'd suggest you try one of these :
- convert your HVM domU to PV. Easiest when running Linux domU. This
has additional benefit of giving you maximum possible speed with
regards to CPU, disk, and network.
- use PV drivers. For Windows HVM, use James Harper's GPLPV. For Linux
HVM, you might be able to find kmod-xenpv RPM or a module called
xennet or xen-vnif
- use stubdom (only available on Xen 3.3)

As per your suggestions, I used suggestion 1 (i.e. of using PV based domU) and
it worked fine and I was able to get about 900 Mbps throughput on a 1 g card.  On
the other hand on fully virtualized thing I was getting about 40 Mbps on average.  So
the difference was substantial.

Though I have one question.  By "PARA-VIRTUALIZATION" I understand that, the
guest OS code is change such that the conventional assumption of OS that it is
running in ring 0 goes away.  I used FC8 as dom0 and the same FC8 DVD worked
for domU, while selecting para-virtualized option.  So I am surprized did Xen changed
the required Linux Kernel stuff in the guest, on the fly?  Or did FC distribution had
the support to be used as para-virtualized guest?

Thank you,
Abdul Qadeer
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