Re: [Xen-users] DomU Fails when network load is high

["Chris Holland" <rangerco1@xxxxxxxxx>]

Hello,

Not sure how much this would help, although it is good to know.  The DomU that is failing does not cause any major disk IO. It is simply an internet gateway with one interface connected to the internet and the other connected to my physical home switch.  Also, there doesn't seem to be anything in the logs on either the DomU or Dom0. It just dies.

Thanks
Chris

On Wed, Jul 23, 2008 at 8:26 PM, Steve Wray <steve.wray@xxxxxxxxx> wrote:

Chris Holland wrote:

Hello,

I am using Gentoo 2008.1 with Xen 3.2.1
I am having an unusual problem with a DomU, it is setup as a router. The DomU is connected to 2 NICs, one of which is connected to the outside and the other to the internal network.
When I pass a large amount of data through this DomU like a large torrent download for example, the DomU simply dies with no errors or any indication. It just fails and I have to
re-create the vm.
If any more info is needed please let me know and I will provide it.

I've seen problems with high network load and simultaneous high I/O load on the disk. This was affecting drbd replication very badly.

The solution I found was to use the 'rate' parameter on the VIF eg:

vif = [ "rate=20MB/s,mac=00:16:3e:00:01:02, bridge=xenbr2",
       "rate=20MB/s,mac=00:16:3e:00:00:02 ,bridge=xenbr0" ]

no other tuning gave any improvement, from disabling tcpchecksum offloading to all manner of sysctl tweaking.

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users