从快照 AMI 创建 AWS EC2 实例，启动后缺少 eth0

Question

我最近从我们的生产 EC2 的快照创建了一个新的 EC2。

机器启动良好，但我可以通过 ssh 登录 - 无法通过其他任何方式访问。没有万维网，什么都没有。

在进一步检查设备后，主要是网络堆栈 - 我看到了这一点：

/etc/udev/rules.d/70-persistent-net.rules

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="06:68:f3:22:91:f2", NAME="ens5"

如果配置

ens5: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
        inet 172.31.12.146  netmask 255.255.240.0  broadcast 172.31.15.255
        inet6 fe80::468:f3ff:fe22:91f2  prefixlen 64  scopeid 0x20<link>
        ether 06:68:f3:22:91:f2  txqueuelen 1000  (Ethernet)
        RX packets 492  bytes 81928 (80.0 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 474  bytes 76982 (75.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 6  bytes 416 (416.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 6  bytes 416 (416.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

请注意.env 文件第一行的ens5ifconfig。

[/etc] #服务网络重启

Restarting network (via systemctl):  Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.
                                                       [FAILED]

[/etc] # systemctl status network.service

? network.service - LSB: Bring up/down networking
   Loaded: loaded (/etc/rc.d/init.d/network; bad; vendor preset: disabled)
   Active: failed (Result: exit-code) since Tue 2018-10-16 11:13:34 EDT; 1min 4s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 2223 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=1/FAILURE)
   CGroup: /system.slice/network.service
           ??857 /sbin/dhclient -1 -q -lf /var/lib/dhclient/dhclient--ens5.lease -pf /var/run/dhclient-ens5.pid -H ip-172-31-12-146 ens5

Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal network[2223]: RTNETLINK answers: File exists
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal network[2223]: RTNETLINK answers: File exists
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal network[2223]: RTNETLINK answers: File exists
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal network[2223]: RTNETLINK answers: File exists
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal network[2223]: RTNETLINK answers: File exists
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal network[2223]: RTNETLINK answers: File exists
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal systemd[1]: network.service: control process exited, code=exited status=1
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal systemd[1]: Failed to start LSB: Bring up/down networking.
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal systemd[1]: Unit network.service entered failed state.
Oct 16 11:13:34 ip-172-31-12-146.us-west-1.compute.internal systemd[1]: network.service failed.

它找不到 eth0，也无法重新启动网络堆栈。我试过重新启动机器，关闭并启动，但没有运气。我错过了什么？

Answer 1

您是否从旧实例类型更改为 T3 / M5 / C5？它们具有不同的硬件并使用不同的设备名称。

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一种选择是重新配置网络堆栈以反映新的设备名称 - 这可能是一项艰巨的任务，除非您\xe2\x80\x99 是熟练的 Linux 管理员并且知道自己在做什么。

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或者，更简单的是，将实例类型更改为您创建快照的实例类型。这应该将设备名称修复回原来的名称。

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您可以更改大小，例如从大更改为中，但保留类型 - 如果是 T2，请再次使用 T2。

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另外，我建议您将其从快照恢复到一个新的实例 - 当前的实例可能已尝试适应新的设备名称，并且可能处于不一致的状态。最好从产品快照重新开始。

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希望有帮助:)

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