将 16.04 服务器更新到 18.04.1，现在我看到有关丢失文件、无法解析 dns、无法连接到总线的奇怪错误

Question

好的，这是从 16.04.1 LTS 到 18.04.1 LTS 的升级，服务器是无头的。升级完成并重新启动后，会发生以下情况：

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尝试升级软件包只会导致以下结果：

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~$ sudo apt upgrade\nReading package lists... Done\nBuilding dependency tree\nReading state information... Done\nCalculating upgrade... Done\nThe following packages will be upgraded:\n  policykit-1 screen smartmontools\n3 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.\n1 not fully installed or removed.\nNeed to get 0 B/1,081 kB of archives.\nAfter this operation, 147 kB of additional disk space will be used.\nDo you want to continue? [Y/n] y\n\n(Reading database ... 159133 files and directories currently installed.)\nPreparing to unpack .../smartmontools_6.5+svn4324-1_amd64.deb ...\nFailed to connect to bus: No such file or directory\n[...]\n

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它所说的是 Dbus 吗？\n无论如何，恢复怎么样？

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~$ sudo apt update\nErr:1 http://security.ubuntu.com/ubuntu bionic-security InRelease\n  Temporary failure resolving \'security.ubuntu.com\'\nErr:2 http://se.archive.ubuntu.com/ubuntu bionic InRelease\n  Temporary failure resolving \'se.archive.ubuntu.com\'\nErr:3 http://se.archive.ubuntu.com/ubuntu bionic-updates InRelease\n  Temporary failure resolving \'se.archive.ubuntu.com\'\nErr:4 http://se.archive.ubuntu.com/ubuntu bionic-backports InRelease\n  Temporary failure resolving \'se.archive.ubuntu.com\'\nReading package lists... Done\nBuilding dependency tree\nReading state information... Done\n1 package can be upgraded. Run \'apt list --upgradable\' to see it.\nW: Failed to fetch http://se.archive.ubuntu.com/ubuntu/dists/bionic/InRelease  Temporary failure resolving \'se.archive.ubuntu.com\'\nW: Failed to fetch http://se.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  Temporary failure resolving \'se.archive.ubuntu.com\'\nW: Failed to fetch http://se.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease  Temporary failure resolving \'se.archive.ubuntu.com\'\nW: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRelease  Temporary failure resolving \'security.ubuntu.com\'\nW: Some index files failed to download. They have been ignored, or old ones used instead.\n

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什么？是不是dns坏了？

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~$ wget www.google.com\n--2018-11-10 01:55:16--  http://www.google.com/\nResolving www.google.com (www.google.com)... failed: Temporary failure in name resolution.\nwget: unable to resolve host address \xe2\x80\x98www.google.com\xe2\x80\x99\n

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看起来是这样。嗯，ifconfig 不显示 dns。谷歌引导我回答这个问题，让我们尝试一下。

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~$ systemd-resolve --status\nsd_bus_open_system: No such file or directory\n

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好吧，我现在越来越迷失了。Google现在发现这个问题，是关于docker的，这不是我的情况，但也提到了一个systemd不是pid 1的问题：

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~$ ps aux\nUSER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND\nroot         1  0.1  0.1 159752  9116 ?        Ss   01:25   0:02 /sbin/init splash nomdmonddf nomdmonisw\nroot         2  0.0  0.0      0     0 ?        S    01:25   0:00 [kthreadd]\nroot         3  0.0  0.0      0     0 ?        S    01:25   0:00 [ksoftirqd/0]\nroot         5  0.0  0.0      0     0 ?        S<   01:25   0:00 [kworker/0:0H]\nroot         7  0.0  0.0      0     0 ?        S    01:25   0:00 [rcu_sched]\nroot         8  0.0  0.0      0     0 ?        S    01:25   0:00 [rcu_bh]\nroot         9  0.0  0.0      0     0 ?        S    01:25   0:00 [migration/0]\nroot        10  0.0  0.0      0     0 ?        S    01:25   0:00 [watchdog/0]\nroot        11  0.0  0.0      0     0 ?        S    01:25   0:00 [watchdog/1]\n[...]\n

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我猜？这是根本问题，还是表象？我怎样才能解决这个问题？

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Answer 1

升级到 18.04.01 后，我在一台 OVH VPS 服务器上遇到了同样的错误。我有其他非常相似的服务器在升级后工作正常，这帮助我解决了这个问题。

走进兔子洞并注意到：

sudo systemctl
...
systemd-logind.service     loaded failed failed
...

这引导我到这个网站： https://forum.proxmox.com/threads/systemd-logind-failures.44219/

我确认我的 /var/run 没有符号链接到 /run ，它位于其他服务器上。这个在两个地方都有文件。

我几乎按照建议进行符号链接，修复了每一行中的“目录不为空”错误：

mv -f /var/run/sudo/ts/* /run/sudo/ts/; rm -rf /var/run/sudo/ts; 
mv -f /var/run/sudo/* /run/sudo/; rm -rf /var/run/sudo; 
mv -f /var/run/* /run/; rm -rf /var/run; 
ln -s /run /var/run;
reboot

此步骤解决了部分问题，例如：

$ systemd-resolve --status

但是 DNS 解析仍然失败，但使用解析工作正常：

$ ping google.com
ping: google.com: Temporary failure in name resolution

$ systemd-resolve google.com
google.com: 216.58.213.174

根据https://superuser.com/questions/1317623/nslookup-failed-but-systemd-resolved-works中的建议

我将 /etc/resolv.conf 符号链接从 更改/run/resolvconf/resolv.conf为/run/systemd/resolve/resolv.conf

$ ls -l /etc/resolv.conf
lrwxrwxrwx 1 root root 29 Feb 24  2017 /etc/resolv.conf -> ../run/resolvconf/resolv.conf

$ sudo rm /etc/resolv.conf
$ sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

$ ping google.com
PING google.com (216.58.204.238) 56(84) bytes of data.
64 bytes from par21s06-in-f14.1e100.net (216.58.204.238): icmp_seq=1 ttl=53 time=9.11 ms

现在一切正常。