systemd-journald无法在CentOS 7上启动

从一周前开始,期刊就不再完成了.启动时,它会启动并记录引导消息和一些其他服务启动日志,然后在启动Switch Root时突然关闭：

Mar 18 05:22:56 playground1.local systemd-journal[96]: Runtime journal is using 8.0M (max allowed 391.1M,trying to leave 586.7M free of 3.8G available → current limit 391.1M).
Mar 18 05:22:56 playground1.local systemd-journal[96]: Runtime journal is using 8.0M (max allowed 391.1M,trying to leave 586.7M free of 3.8G available → current limit 391.1M).
Mar 18 05:22:56 playground1.local kernel: Initializing cgroup subsys cpuset
Mar 18 05:22:56 playground1.local kernel: Initializing cgroup subsys cpu
Mar 18 05:22:56 playground1.local kernel: Initializing cgroup subsys cpuacct
Mar 18 05:22:56 playground1.local kernel: Linux version 3.10.0-327.10.1.el7.x86_64 ([e-mail]) (gcc version 4.8.3 20140911 (Red Hat 4.8.3-9) (GCC) ) #1 SMP Tue Feb 16 17:03:50 UTC 2016
Mar 18 05:22:56 playground1.local kernel: Command line: BOOT_IMAGE=/vmlinuz-3.10.0-327.10.1.el7.x86_64 root=/dev/mapper/centos-root ro rd.lvm.lv=centos/root rd.lvm.lv=centos/swap crashkernel=auto rhgb quiet LANG=en_US.UTF-8 console=ttyS0 systemd.debug

...

Mar 18 05:22:57 playground1.local systemd[1]: Reached target Switch Root.
Mar 18 05:22:57 playground1.local systemd[1]: Starting Switch Root.
Mar 18 05:22:57 playground1.local systemd[1]: Starting Switch Root...
Mar 18 05:22:57 playground1.local systemd[1]: Switching root.
Mar 18 05:22:57 playground1.local systemd-journal[96]: Journal stopped

如果我尝试手动启动它,它会很快失败：

[root@playground1 ~]# systemctl start systemd-journald.service
Job for systemd-journald.service failed because the control process exited with error code. See "systemctl status systemd-journald.service" and "journalctl -xe" for details.
[root@playground1 ~]# systemctl status systemd-journald.service
● systemd-journald.service - Journal Service
  Loaded: loaded (/usr/lib/systemd/system/systemd-journald.service; static; vendor preset: disabled)
  Active: failed (Result: start-limit) since Fri 2016-03-18 16:38:21 EDT; 21s ago
    Docs: man:systemd-journald.service(8)
          man:journald.conf(5)
  Process: 3404 ExecStart=/usr/lib/systemd/systemd-journald (code=exited,status=1/FAILURE)
Main PID: 3404 (code=exited,status=1/FAILURE)
  Status: "Shutting down..."
[root@playground1 ~]#

journalctl -xe打印引导日志,当手动启动服务时,它无法实际向日志写入任何内容.如果我删除了日志文件,则不会创建它.

手动运行/usr/lib / systemd / systemd-journald工作,意味着进程已启动,而journalctl包含journald启动日志,但之后实际上没有其他内容记录.

systemd-journald.socket似乎也无法加载,它可能是失败的原因,但我在日志中没有看到任何关于它的内容：

[root@playground1 systemd]# systemctl status systemd-journald.socket
● systemd-journald.socket - Journal Socket
  Loaded: loaded (/usr/lib/systemd/system/systemd-journald.socket; static; vendor preset: disabled)
  Active: failed (Result: service-failed-permanent) since Fri 2016-03-18 16:46:24 EDT; 4min 8s ago
    Docs: man:systemd-journald.service(8)
          man:journald.conf(5)
  Listen: /run/systemd/journal/stdout (Stream)
          /run/systemd/journal/socket (Datagram)
          /dev/log (Datagram)

我不认为它与SELinux有关,因为唯一被拒绝的是读取机器ID,这不应该是一个showstopper.但是,我在审核日志中注意到的一个奇怪的事情是该服务似乎开始了两次？

type=AVC msg=audit(1458334641.993:330): avc:  denied  { read } for  pid=3689 comm="systemd-journal" name="machine-id" dev="dm-0" ino=67109045 scontext=system_u:system_r:syslogd_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=file
type=SYSCALL msg=audit(1458334641.993:330): arch=c000003e syscall=2 success=no exit=-13 a0=7fbc38ebf08f a1=80100 a2=7ffeb87c80bf a3=3 items=0 ppid=1 pid=3689 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="systemd-journal" exe="/usr/lib/systemd/systemd-journald" subj=system_u:system_r:syslogd_t:s0 key=(null)
type=SERVICE_START msg=audit(1458334642.002:331): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=systemd-journald comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed'
type=SERVICE_START msg=audit(1458334642.002:332): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=systemd-journald comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
type=SERVICE_STOP msg=audit(1458334642.002:333): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=systemd-journald comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'

查看两条SERVICE_START消息,一条res =失败,另一条res = success.

谷歌告诉我没有其他人有这个问题.有任何想法吗？

AVC表示正在读取的文件没有SELinux标签.

如果在创建文件时禁用SELinux,或者如果它是在不支持SELinux的文件系统上创建(例如vfat),则会发生这种情况.

如果某人已经禁用并重新启用SELinux,那么您应该能够通过重新标记文件系统来解决问题(可能还有许多其他问题).您可以在线完成以下操作：

restorecon -r /

如果文件所在的文件系统不支持SELinux,则需要将其替换为支持SELinux的文件系统,然后重新标记.