On Dec 5, 2007, at 10:05 AM, Simon Gao wrote: > I also saw the similar problem. However, it happens with I have > several > KVM guests running and sharing the same network bridge. If just one > single KVM guest, then everything works fine. > > Simon
I think I've been through similar problems as well. Initially my guests would experience massive packet losses and huge delays somtime shortly after the second guest started. Often the first guest continued to operate fairly well, but it was noticably degraded. That is when I switched from the default QEMU ne2k device to the rtl8139 for all my virtual network taps. A bunch of debugging eventually led me to check the mac addresses of all my guests on the bridge. Not the host side TAP address, but the guest's mac address. In my environment I found cases where more than one of the guests on the bridge had the same mac address and rewrote my startup scripts and configs to always assign a unique mac address to each network device. I thought perhaps this may be related to something in KVM-55, but I've just shutdown and restarted my VMs on the KVM-55 modules and userspace and am not seeing any network problems with my VMs. Here are the kvm/qemu command lines for 3 of my machines: (2 FreeBSD-6.2 servers and a Ubuntu-7.10 server) > /usr/local/bin/qemu-system-x86_64 -name FreeBSD_6.2 -hda /vm_img/ > bsd_dz1/disk0.qcow -m 256 -boot c -smp 1 -usb -usbdevice tablet - > vnc :0 -serial telnet::4100,server,nowait -monitor telnet:: > 4200,server,nowait -net > nic,vlan=0,macaddr=52:54:00:12:34:56,model=rtl8139 -net > tap,vlan=0,ifname=tap0,script=/etc/kvm/kvm-ifup -net > nic,vlan=1,model=rtl8139 -net tap,vlan=1,ifname=dmz0,script=/etc/ > kvm/kvm-ifup > /usr/local/bin/qemu-system-x86_64 -name DOM9-BSD62 -hda /vm_img/ > bsd_in1/dom9-disk1.qcow -hdb /vm_img/bsd_in1/dom9-disk2.raw -m 512 - > boot c -smp 2 -usb -usbdevice tablet -vnc :9 -serial telnet:: > 4109,server,nowait -monitor telnet::4209,server,nowait -net > nic,vlan=0,macaddr=52:54:09:12:34:56,model=rtl8139 -net > tap,vlan=0,ifname=tap1,script=/etc/kvm/kvm-ifup > /usr/local/bin/qemu-system-x86_64 -name DOMT2-UbuSrv7.10 -hda /dev/ > vg_r5/dom_t2 -m 512 -boot c -smp 1 -vnc :8 -serial telnet:: > 4108,server,nowait -monitor telnet::4208,server,nowait -net > nic,vlan=0,macaddr=52:54:08:12:34:56,model=rtl8139 -net > tap,vlan=0,ifname=tap2,script=/etc/kvm/kvm-ifup The kvm-ifup script referenced in these commands is very similar to the standard qemu-ifup except that it deals with multiple bridges, based on the interface name. It may be worth noting that I'm not explicitly assigning a mac address to interface dmz0 in the first example, but other interfaces on that network all have unique mac addresses so it isn't critical. You might want to examine the output of 'brctl showmacs br0' (use your bridge name in place of br0) and also check the interface stats on the bridge and any troublesome tap interfaces. Lynn Kerby San Martin, CA ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
