Network Broke For A While When Libvirtd Start
When start service libvirtd by
service libvirtd start
the network will broke for a while and then reconnected. Following is /var/log/messages:
Feb 24 13:28:51 node-0 kernel: lo: Dropping TSO features since no CSUM feature. Feb 24 13:28:51 node-0 kernel: lo: Disabled Privacy Extensions Feb 24 13:28:51 node-0 kernel: virbr0: Dropping TSO features since no CSUM feature. Feb 24 13:28:51 node-0 kernel: virbr0: Dropping TSO6 features since no CSUM feature. Feb 24 13:28:51 node-0 kernel: device virbr0-nic entered promiscuous mode Feb 24 13:28:51 node-0 kernel: virbr0: starting userspace STP failed, starting kernel STP
Feb 24 13:28:51 node-0 kernel: ip_tables: (C) 2000-2006 Netfilter Core Team Feb 24 13:28:51 node-0 kernel: nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
Feb 24 13:28:51 node-0 kernel: virbr0: topology change detected, propagating Feb 24 13:28:51 node-0 kernel: virbr0: port 1(virbr0-nic) entering forwarding state Feb 24 13:28:51 node-0 kernel: 8021q: adding VLAN 0 to HW filter on device virbr0
Feb 24 13:28:51 node-0 kernel: ixgbe 0000:02:00.0: eth2: detected SFP+: 3
Feb 24 13:28:52 node-0 kernel: ixgbe 0000:02:00.1: eth3: detected SFP+: 4
Feb 24 13:28:52 node-0 kernel: bonding: bond0: link status definitely down for interface eth2, disabling it Feb 24 13:28:52 node-0 kernel: virbr0: port 1(virbr0-nic) entering disabled state Feb 24 13:28:52 node-0 kernel: bonding: bond0: link status definitely down for interface eth3, disabling it Feb 24 13:28:53 node-0 kernel: ixgbe 0000:02:00.0: eth2: NIC Link is Up 10 Gbps, Flow Control: RX/TX
Feb 24 13:28:53 node-0 kernel: bond0: link status definitely up for interface eth2, 10000 Mbps full duplex. Feb 24 13:28:53 node-0 kernel: ixgbe 0000:02:00.1: eth3: NIC Link is Up 10 Gbps, Flow Control: RX/TX
Feb 24 13:28:53 node-0 kernel: bond0: link status definitely up for interface eth3, 10000 Mbps full duplex.
OS: CentOS 6.5
libvirt: libvirt-daemon-1.2.5-1.mira1.x86_64
Does anyone know the reason?
2 thoughts on - Network Broke For A While When Libvirtd Start
Hello
https://www.redhat.com/mailman/listinfo/libvirt-users is the official mailing list for the libvirt daemon, maybe you can ask in there and get better support.
This mailing list is for the general usage of the CentOS system, I am afraid that not many experts about libvert could be found here.
If you ask in the most appropriate mailing list, you may get the quickest and the most helpful assistance.
Never mind, I have found the reason. When libvirtd started, it will create bridge virbr0 and then write 1 to /proc/sys/net/ipv4/ip_forward (0 in default). Set ip_forward from 0 to 1 will cause ixgbe driver reset NIC, so the network broke for a while.