Re: UDP problem with virtio...

[Erik Brakkee <erik@brakkee.org>]

Hi all,


I have done some more experiments and it does work when using a Centos 
6.2 guest. Therefore, it is most likely a compatibility issues between 
the guest and host virtio implementation.
I read somewhere there is some sort of compatibility mode for virtio but 
could not find how to activate it. Is there a way to make these 
different virtio host/guest implementations talk to each other?

Cheers
   Erik


Erik Brakkee wrote:
> Hi,
>
>
> I am running a guest that exposes a NFS share to be used by a TViX 
> box. The TViX box is not that advanced and uses NFS over UDP instead 
> of TCP.
> What I am seeing is that when I use the virtio network driver, the 
> TViX box cannot mount the filesystem. However, when I use rtl8139 
> instead, it can.
>
> The problem is easily reproduced:
> 1. Create a guest that uses a virtio network interface (bridging setup)
> 2. Expose an NFS share on the guest
> 3. mount the NFS share using 'mount -o udp host:/share /localdir'
> 4. verify that the NFS share cannot be mounted.
> 5. Modify the guest to use rtl8139 device emulation and stop the guest 
> and start it
> 6. mount the NFS share using 'mount -o udp host:/share /localdir'
> 7. Verify tha the NFS share can be mounted
>
> Now the bug reporting guidelines say that I should always use the 
> latest KVM version but compiling KVM from source and using that is not 
> really an option. The server is important enough not to mess around 
> with. Therefore, my question is whether this problem has been seen 
> before or not.
>
> My configuration is as follows:
>
> *Host*
>
> centos 6.2
> uname -a gives "Linux falcon.fritz.box 2.6.32-220.17.1.el6.x86_64 #1 
> SMP Wed May 16 00:01:37 BST 2012 x86_64 x86_64 x86_64 GNU/Linux"
>
> KVM software: qemu-kvm-0.12.1.2-2.209.el6_2.5.x86_64
>
> *Guest*
>
> OpenSuSE 11.3
> uname -a gives "Linux shikra 2.6.34.7-0.7-default #1 SMP 2010-12-13 
> 11:13:53 +0100 x86_64 x86_64 x86_64 GNU/Linux"
>
> I also see in the instructions I should try running qemu with some 
> alternative switches, but I am not running qemu directly. I am using 
> virt-manager and a domain.xml to configure how qemu runs. How should I 
> modify the domain.xml to help in troubleshooting this issue?
>
> Cheers
>   Erik
>
> PS. the domain.xml is attached.
>
>
>
>
>


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