Por que o systemd network.service reclama sobre “Não foi possível carregar o arquivo '/ etc / sysconfig / network-scripts / ifcfg-lo'”

Question

Eu tenho vários novos sistemas CentOS 7 que eu instalei usando o Kickstart.

Quando eu reinicio a rede, noto erros estranhos que dizem " Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo' ". Este erro realmente não faz sentido, porque o arquivo ifcfg-lo existe, e parece normal para mim. O sistema parece estar funcionando normalmente, então por que o serviço de rede está reclamando?

[root@host3 ~]# cat /etc/sysconfig/network-scripts/ifcfg-lo 
DEVICE=lo
IPADDR=127.0.0.1
NETMASK=255.0.0.0
NETWORK=127.0.0.0
# If you're having problems with gated making 127.0.0.0/8 a martian,
# you can change this to something else (255.255.255.255, for example)
BROADCAST=127.255.255.255
ONBOOT=yes
NAME=loopback
[root@host3 ~]#


[root@host3 ~]# systemctl restart network
[root@host3 ~]# journalctl -xe -u network.service
...
-- Subject: Unit network.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit network.service has begun starting up.
Sep 30 15:02:56 host3.example.org network[36432]: Bringing up loopback interface:  Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'
Sep 30 15:02:56 host3.example.org network[36432]: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'
Sep 30 15:02:56 host3.example.org network[36432]: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'
Sep 30 15:02:56 host3.example.org network[36432]: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'
Sep 30 15:02:56 host3.example.org network[36432]: [  OK  ]
Sep 30 15:02:56 host3.example.org network[36432]: Bringing up interface eth0:  Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/3)
Sep 30 15:02:56 host3.example.org network[36432]: [  OK  ]
Sep 30 15:02:56 host3.example.org systemd[1]: Started LSB: Bring up/down networking.
-- Subject: Unit network.service has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit network.service has finished starting up.
-- 
-- The start-up result is done.
[root@host3 ~]#

Atualize respondendo à pergunta de @ SmallLoanOf1M. O dispositivo atual parece estar ativo e em execução após a inicialização. O campo 'UNKNOWN' parece ser normal, até onde eu sei.

[root@host3 ~]# ip addr show dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
[root@host3 ~]#

    

Answer 1

Isso está sendo rastreado atualmente como um bug pela Red Hat, veja este artigo .

Corrigir: Adicione NM_CONTROLLED=no a /etc/sysconfig/network-scripts/ifcfg-lo .

Causa raiz: O plugin ifcfg-rh no NetworkManager não suporta o tipo de interface de loopback e registra uma mensagem sobre ele no log do sistema.