1. Failed to restart mongod.service: Unit mongod.service not found.

解決方法：

Most probably unit mongodb.service is masked. Use following command to unmask it.

sudo systemctl unmask mongodb

and re-run

sudo service mongod start

 1 vagrant@homestead:~$ sudo service mongod restart
 2 Failed to restart mongod.service: Unit mongod.service not found.
 
 3 vagrant@homestead:~$ ^C
 4 vagrant@homestead:~$ sudo systemctl unmask mongodb
 5 Removed symlink /etc/systemd/system/mongodb.service.
 6 vagrant@homestead:~$ sudo service mongod start
 7 vagrant@homestead:~$ sudo service mongod status
 8 ● mongod.service - MongoDB Database Server
 9    Loaded: loaded (/lib/systemd/system/mongod.service; disabled; vendor preset: enabled)
 
10    Active: active (running) since Thu 2018-10-25 03:50:52 UTC; 5s ago
11      Docs: https://docs.mongodb.org/manual
12  Main PID: 6669 (mongod)
13     Tasks: 19
14    Memory: 37.9M
15       CPU: 85ms
16    CGroup: /system.slice/mongod.service
17            └─6669 /usr/bin/mongod --config /etc/mongod.conf
18 
19
 
 Oct 25 03:50:52 homestead systemd[1]: Started MongoDB Database Server.
20 Oct 25 03:50:52 homestead mongod[6669]: 2018-10-25T03:50:52.045+0000 I CONTROL  [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 spe
21 lines 1-13/13 (END)

Mongodb 安裝錯誤匯總