报错记录如下
[root@mongodb3 ~]# systemctl start mongod Authorization not available. Check if polkit service is running or see debug message for more information.Failed to start mongod.service: Connection timed outSee system logs and 'systemctl status mongod.service' for details.[root@mongodb3 ~]# systemctl status mongod.service● mongod.service - SYSV: Mongo is a scalable, document-oriented database.Loaded: loaded (/etc/rc.d/init.d/mongod; bad; vendor preset: disabled)Active: inactive (dead)Docs: man:systemd-sysv-generator(8)[root@mongodb3 ~]# systemctl start mongod Authorization not available. Check if polkit service is running or see debug message for more information.Failed to start mongod.service: Connection timed outSee system logs and 'systemctl status mongod.service' for details.[root@mongodb3 ~]# systemctl status polkit● polkit.service - Authorization ManagerLoaded: loaded (/usr/lib/systemd/system/polkit.service; static; vendor preset: enabled)Active: failed (Result: timeout) since Tue -02-04 19:07:15 CST; 9h agoDocs: man:polkit(8)Process: 6867 ExecStart=/usr/lib/polkit-1/polkitd --no-debug (code=killed, signal=TERM)Main PID: 6867 (code=killed, signal=TERM)Feb 04 19:05:27 mongodb3 systemd[1]: Starting Authorization Manager...Feb 04 19:05:29 mongodb3 polkitd[6867]: Started polkitd version 0.112Feb 04 19:06:43 mongodb3 polkitd[6867]: Loading rules from directory /etc/polkit-1/rules.dFeb 04 19:06:43 mongodb3 polkitd[6867]: Loading rules from directory /usr/share/polkit-1/rules.dFeb 04 19:06:43 mongodb3 polkitd[6867]: Finished loading, compiling and executing 11 rulesFeb 04 19:06:43 mongodb3 polkitd[6867]: Acquired the name org.freedesktop.PolicyKit1 on the system busFeb 04 19:07:15 mongodb3 systemd[1]: polkit.service start operation timed out. Terminating.Feb 04 19:07:15 mongodb3 systemd[1]: Failed to start Authorization Manager.Feb 04 19:07:15 mongodb3 systemd[1]: Unit polkit.service entered failed state.Feb 04 19:07:15 mongodb3 systemd[1]: polkit.service failed.[root@mongodb3 ~]# systemctl stop polkit Authorization not available. Check if polkit service is running or see debug message for more information.Failed to stop polkit.service: Connection timed outSee system logs and 'systemctl status polkit.service' for details.Failed to get load state of polkit.service: Connection timed out
出现问题，就需要解决问题，不能较真的不断尝试…
1. /var/log/mongodb/mongod.log 日志中并没有先的日志产生
polkit 这个是什么服务？
参考网站
/index.php/Polkit_(%E7%AE%80%E4%BD%93%E4%B8%AD%E6%96%87)
/software/polkit/docs/latest/polkit.8.html
大概知道
polkit是linux服务器上的身份认证组件，目的是让用户证明自己属于某个用户组。更详细的内容，可以参考上面的网址。
经过百度，找到解决方法
PolicyKit failing to start with error: polkit.service: main process exited, code=exited, status=1/FAILURE
1.Ensure the existence of a polkitd system user & group
Copy/paste the following 2 compound-commands to a root terminal to check for and conditionally create the user/group
getent group polkitd >/dev/null && echo -e "\e[1;32mpolkitd group already exists\e[0m" || {groupadd -r polkitd && echo -e "\e[1;33mAdded missing polkitd group\e[0m" || echo -e "\e[1;31mAdding polkitd group FAILED\e[0m"; }getent passwd polkitd >/dev/null && echo -e "\e[1;32mpolkitd user already exists\e[0m" || {useradd -r -g polkitd -d / -s /sbin/nologin -c "User for polkitd" polkitd && echo -e "\e[1;33mAdded missing polkitd user\e[0m" || echo -e "\e[1;31mAdding polkitd user FAILED\e[0m"; }
2.Reset the permissions and user/group ownership for all files provided by the polkit and polkit-pkla-compat packages
Copy/paste the following compound-command to a root terminal to check for and conditionally reset user/group perms & ownership
rpm -Va polkit\* && echo -e "\e[1;32mpolkit* rpm verification passed\e[0m" || {echo -e "\e[1;33mResetting polkit* rpm user/group ownership & perms\e[0m"; rpm --setugids polkit polkit-pkla-compat; rpm --setperms polkit polkit-pkla-compat; }
3.Reboot
A reboot of the machine will be required to make sure that all changes take affect and that polkit has reconnected to the dbus
shutdown -r now
重启服务之后，启动mongod服务，启动正常
```bash[root@mongodb3 ~]# systemctl start mongod[root@mongodb3 ~]# mongo --port 27017 -u "admin" -p "admin" --authenticationDatabase "admin"MongoDB shell version: 3.2.22connecting to: 127.0.0.1:27017/testServer has startup warnings: -02-05T05:14:44.741+0800 I CONTROL [initandlisten] -02-05T05:14:44.741+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.-02-05T05:14:44.741+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'-02-05T05:14:44.741+0800 I CONTROL [initandlisten] -02-05T05:14:44.741+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.-02-05T05:14:44.741+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'-02-05T05:14:44.741+0800 I CONTROL [initandlisten] -02-05T05:14:44.741+0800 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.-02-05T05:14:44.741+0800 I CONTROL [initandlisten] replSet:SECONDARY>
