Re: Loss of network connectivity with high load

[Brian Jackson <iggy@theiggy.com>]

On Tuesday 15 June 2010 16:00:38 Daniel Bareiro wrote:
> Hi all!
> 
> I'm using Linux 2.6.31.13 compiled with the kernel.org source code on
> KVM host with Debian GNU/Linux Lenny amd64. Also I'm using Debian
> GNU/Linux Lenny amd64 virtual machine with kernel 2.6.26-2 from Debian
> repositories. I'm using qemu-kvm 0.12.3.
> 
> These are the parameters I'm using to start the virtual machine:
> 
> 
> escher:~# ps ax|grep kvm
>  6299 ?        Rl   113:40 /usr/local/qemu-kvm/bin/qemu-system-x86_64
> -drive file=/dev/vm/belvedere-raiz,cache=none,if=virtio,boot=on -drive
> file=/dev/vm/belvedere-u01,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u02,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u03,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u04,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u05,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u06,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u07,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u08,cache=none,if=virtio -drive
> file=/dev/vm/belvedere-u09,cache=none,if=virtio -m 3072 -smp 2 -net
> nic,model=virtio,macaddr=00:16:3e:00:00:56 -net tap -daemonize -vnc :2
> -k es -localtime -monitor telnet:localhost:4002,server,nowait -serial
> telnet:localhost:4042,server,nowait
> 
> 
> When I try to copy directories of several gigabytes in this VM using
> rsync to other hosts, this virtual machine loses connectivity with the
> rest of the network. Checking, using a serial console connection,
> /var/log/syslog and /var/log/messages in search of the problem, I don't
> see information that might give a clue to the problem.
> 
> This problem is not with the network driver by default (rtl8139), so I
> think that should be something related to Virtio.


There have been a few bugs similar to this reported that should be pretty easy 
to find. Basically, I'd say try 0.12.4, it should have a few fixes in this 
area over 0.12.3.


> 
> Thanks in advance for your reply.
> 
> Regards,
> Daniel