Hi Kunpeng, When you reboot the VM with two physical pci-passthrough NICs, ovs-vswtichd is restarted and the interfaces and bridges are down. The virtual networks used by the VMs are based on these interfaces and bridges. So other VMs will lost connections. Typically you should not pass through a PCI device which is bound to DPDK to the VM. Are the 2 network ports which is used to passthrough to the VM bound to DPDK? If so, could you please try OVS-DPDK with the following network topology: 2 network port without DPDK > VM 2 network port with DPDK > Data Network 1 network port without DPDK > OAM Best Regards, Xu, Chenjie From: 张鲲鹏 [mailto:zhang.kunpeng@99cloud.net] Sent: Tuesday, July 16, 2019 3:54 PM To: starlingx-discuss@lists.starlingx.io Subject: [Starlingx-discuss] [Starlingx-disscuss][ovs-dpdk] Reboot instance with physical pci-passthrough NIC causes OVS restart Hi guys, Recently I got a strange problem in StarlingX. When I reboot one VM with two physical pci-passthrough NICs, then all of VMs cannot be connected. I lost connections with all VMs and also the VMs lost each others. Below is the StarlingX environment. 1. stx1.0 version, bootimage[1] 2. Simplex deployment 3. 5 Network ports. Only one don’t support DPDK，and it is used to OAM Network. In the rest, two are used to data network, and another two are used to passthrough to a VM. 4. The VM was attached two more virtual networks. I have tested the case of attaching one virtual net, it was no problem. When I reboot the VM, something were happened. The interfaces and bridges were down, all the virtual dhcp services were down and ovs-vswitchd was restarted. But when I up the interfaces and dhcp services and reboot the other VMs, I have got the connections with them again. It’s ok when to reboot the VM without physical NIC. We think it may be caused by ovs-dpdk, so we stop to use ovs-dpdk and start the ovs manually, the problem was gone. I cannot understand the problem, anybody could give me some comments for it? Thanks a lot. [1] http://mirror.starlingx.cengn.ca/mirror/starlingx/r2018.10/centos/2018.10.0/... Kunpeng