[自分用メモ][Ubuntu][openvswitch] 「ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)」が出力される。

$ systemctl status networking.service -l
● networking.service - LSB: Raise network interfaces.
Loaded: loaded (/etc/init.d/networking)
Drop-In: /run/systemd/generator/networking.service.d
└─50-insserv.conf-$network.conf
/lib/systemd/system/networking.service.d
└─systemd.conf
Active: active (exited) since Sun 2015-05-24 17:47:16 JST; 15min ago
Docs: man:systemd-sysv-generator(8)
Process: 881 ExecStart=/etc/init.d/networking start (code=exited, status=0/SUCCESS)

May 24 17:47:13 ubuntu-virt.kometch.local ovs-vsctl[1261]: ovs|00001|vsctl|INFO|Called as ovs-vsctl --timeout=5 -- --may-exist add-br ovsbr0 --
May 24 17:47:13 ubuntu-virt.kometch.local networking[881]: ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)
May 24 17:47:16 ubuntu-virt.kometch.local ovs-vsctl[1455]: ovs|00001|vsctl|INFO|Called as ovs-vsctl --timeout=5 -- --fake-iface add-bond ovsbr0 bond0 enp5s0f0 enp5s0f1 other_config:bond-detect-mode=miimon bond_mode=balance-slb bond_updelay=100 bond_downdelay=100 other_config:lacp-time=fast other_config:bond-miimon-interval=100 bond_fake_iface=true other_config:bond-detect-mode=miimon "other_config:bond-miimon-interval=\"100\"" --
May 24 17:47:16 ubuntu-virt.kometch.local networking[881]: ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)
May 24 17:47:16 ubuntu-virt.kometch.local ovs-vsctl[1581]: ovs|00001|vsctl|INFO|Called as ovs-vsctl --timeout=5 -- --fake-iface add-bond ovsbr0 bond0 enp5s0f0 enp5s0f1 bond_mode=balance-slb bond_updelay=100 bond_downdelay=100 other_config:lacp-time=fast other_config:bond-miimon-interval=100 other_config:bond-detect-mode=miimon bond_fake_iface=true other_config:bond-detect-mode=miimon "other_config:bond-miimon-interval=\"100\"" --
May 24 17:47:16 ubuntu-virt.kometch.local networking[881]: ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)
May 24 17:47:16 ubuntu-virt.kometch.local networking[881]: Cannot find device "ovsbr0"
May 24 17:47:16 ubuntu-virt.kometch.local networking[881]: Failed to bring up ovsbr0.
May 24 17:47:16 ubuntu-virt.kometch.local networking[881]: ...done.
May 24 17:47:16 ubuntu-virt.kometch.local systemd[1]: Started LSB: Raise network interfaces..

ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)

$ ls -l /var/run/openvswitch/db.sock
srwx------ 1 root root 0 May 24 17:47 /var/run/openvswitch/db.sock

$ tail /var/log/openvswitch/ovsdb-server.log
2015-05-24T08:43:28.121Z|00003|memory|INFO|3252 kB peak resident set size after 10.4 seconds
2015-05-24T08:43:28.121Z|00004|memory|INFO|cells:14 monitors:1 sessions:1
2015-05-24T08:45:00.463Z|00005|jsonrpc|WARN|unix: receive error: Connection reset by peer
2015-05-24T08:45:00.463Z|00006|reconnect|WARN|unix: connection dropped (Connection reset by peer)
2015-05-24T08:45:01.148Z|00007|fatal_signal|WARN|terminating with signal 15 (Terminated)
2015-05-24T08:45:01.148Z|00002|daemon_unix(monitor)|INFO|pid 2202 died, killed (Terminated), exiting
2015-05-24T08:47:20.016Z|00001|vlog|INFO|opened log file /var/log/openvswitch/ovsdb-server.log
2015-05-24T08:47:20.360Z|00002|ovsdb_server|INFO|ovsdb-server (Open vSwitch) 2.3.1
2015-05-24T08:47:30.055Z|00003|memory|INFO|4648 kB peak resident set size after 10.0 seconds
2015-05-24T08:47:30.055Z|00004|memory|INFO|cells:325 monitors:1 sessions:1