I have recently build a vm server based on FC7 and XEN. In my test environment everything seemed fine but in production I am having some major issues with networking.

After an undetermined length of time, I lose access to the external network from the xen quests on the server. They are able to ping the host but nothing external to the server.

The host - dom0 is still fine. I have tried restarting the guests but that doesn't seem to make any difference, rebooting the whole environment seems to be the best way to get things going again.

I am not sure but it would appear it may be load related. I had one guest that had nfs mounts on the host. Networking died very quickly, within 10 minutes. I moved the functions on this guest back into dom0 to stabilise the environment. Now it has been several days since things failed.

It would appear to be an issue in dom0 but I haven't had enough experience with XEM to know. The dom0 kernel is 2.6.20-2936.fc7xen. There are no errors reported anywhere that I have found yet.

WHat kind of guests are you running? Can you post your configuration file of your guest OS? How many NIC's do you have? What are your system specs?

I use OpenSuSE 10.3 and have 2 NIC's. One NIC is dedicated to the Dom0, and the other NIC is for my Xen guest OS's. I run about 4 OS's (2 WIndows Server 2003, Vista, XP) and they have been running rock solid for weeks.

The guests are all FC7 as well as the host, the host is a Supermicro with 2 Broadcom NICs (tg3 driver) and 3Gb of RAM. Only one of the NICs is used and is set at 10half. The server is colocated at a data centre 600miles away !!

The guest configs are as follows with minor variations e.g. amount of ram and disk path. At present there are 3 guests running 1 using 1Gb the other two using 256Mb each. The total network activity is, IMHO, pathetically low so I don't really understand what is happening.


name = "agree-27"
uuid = "f6889dc7-87af-c0e5-2384-bbd6cc644cec"
maxmem = 256
memory = 256
vcpus = 1
bootloader = "/usr/bin/pygrub"
on_poweroff = "destroy"
on_reboot = "restart"
on_crash = "restart"
sdl = 0
vnc = 1
vncunused = 1
disk = [ "tap:aio:/var/lib/VirtualMachines/agree-27.img,xvda,w" ]
vif = [ '' ]