## Clean system:

vagrant@ubuntu20-focal:~$ sudo apt list --installed | grep -c mongo
0

vagrant@ubuntu20-focal:~$ ls -l /lib/systemd/system/mongod.service
ls: cannot access '/lib/systemd/system/mongod.service': No such file or directory

vagrant@ubuntu20-focal:~$ ls -ld /var/lib/mongo
ls: cannot access '/var/lib/mongo': No such file or directory

vagrant@ubuntu20-focal:~$ ls -ld /var/log/mongodb
ls: cannot access '/var/log/mongodb': No such file or directory

vagrant@ubuntu20-focal:~$ ls -l /etc/mongod.conf
ls: cannot access '/etc/mongod.conf': No such file or directory




## Install MDB Enterprise 4.4:

vagrant@ubuntu20-focal:~$ cat /etc/apt/sources.list.d/mongodb-enterprise.list
deb [ arch=amd64,arm64,s390x ] http://repo.mongodb.com/apt/ubuntu focal/mongodb-enterprise/4.4 multiverse


vagrant@ubuntu20-focal:~$ sudo apt-get update
Ign:1 http://repo.mongodb.com/apt/ubuntu focal/mongodb-enterprise/4.4 InRelease
Hit:2 http://repo.mongodb.com/apt/ubuntu focal/mongodb-enterprise/4.4 Release
Hit:3 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease
Get:6 http://archive.ubuntu.com/ubuntu focal-updates InRelease [111 kB]
Get:7 http://archive.ubuntu.com/ubuntu focal-backports InRelease [98.3 kB]
Fetched 210 kB in 1s (258 kB/s)
Reading package lists... Done


vagrant@ubuntu20-focal:~$ sudo apt install mongodb-enterprise


vagrant@ubuntu20-focal:~$ sudo apt list --installed | grep mongo
mongodb-database-tools/focal,now 100.1.1 amd64 [installed,automatic]
mongodb-enterprise-cryptd/focal,now 4.4.0 amd64 [installed,automatic]
mongodb-enterprise-database-tools-extra/focal,now 4.4.0 amd64 [installed,automatic]
mongodb-enterprise-mongos/focal,now 4.4.0 amd64 [installed,automatic]
mongodb-enterprise-server/focal,now 4.4.0 amd64 [installed,automatic]
mongodb-enterprise-shell/focal,now 4.4.0 amd64 [installed,automatic]
mongodb-enterprise-tools/focal,now 4.4.0 amd64 [installed,automatic]
mongodb-enterprise/focal,now 4.4.0 amd64 [installed]


## Missing conf file and dbpath dir:

vagrant@ubuntu20-focal:~$ ls -ld /var/lib/mongo
ls: cannot access '/var/lib/mongo': No such file or directory

vagrant@ubuntu20-focal:~$ ls -ld /var/log/mongodb
drwxr-xr-x 2 mongodb mongodb 4096 Aug  4 18:17 /var/log/mongodb

vagrant@ubuntu20-focal:~$ ls -l /etc/mongod.conf
ls: cannot access '/etc/mongod.conf': No such file or directory



## Installed systemctl unit file references not-installed conf file:

vagrant@ubuntu20-focal:~$ sudo systemctl status mongod.service
● mongod.service - MongoDB Database Server
     Loaded: loaded (/lib/systemd/system/mongod.service; disabled; vendo>
     Active: inactive (dead)
       Docs: https://docs.mongodb.org/manual

Aug 04 18:19:33 ubuntu20-focal systemd[1]: /lib/systemd/system/mongod.se>
vagrant@ubuntu20-focal:~$


vagrant@ubuntu20-focal:~$ grep 'conf' /lib/systemd/system/mongod.service
ExecStart=/usr/bin/mongod --config /etc/mongod.conf

vagrant@ubuntu20-focal:~$ sudo systemctl start mongod

vagrant@ubuntu20-focal:~$ ps -ef | grep -v grep | grep -c mongod
0


vagrant@ubuntu20-focal:~$ sudo grep mongo /var/log/syslog
Aug  4 18:19:33 ubuntu20-focal systemd[1]: /lib/systemd/system/mongod.service:11: PIDFile= references a path below legacy directory /var/run/, updating /var/run/mongodb/mongod.pid → /run/mongodb/mongod.pid; please update the unit file accordingly.
Aug  4 18:20:31 ubuntu20-focal systemd[1]: /lib/systemd/system/mongod.service:11: PIDFile= references a path below legacy directory /var/run/, updating /var/run/mongodb/mongod.pid → /run/mongodb/mongod.pid; please update the unit file accordingly.
Aug  4 18:20:31 ubuntu20-focal mongod[17387]: Error opening config file: Is a directory
Aug  4 18:20:31 ubuntu20-focal mongod[17387]: try '/usr/bin/mongod --help' for more information
Aug  4 18:20:31 ubuntu20-focal systemd[1]: mongod.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Aug  4 18:20:31 ubuntu20-focal systemd[1]: mongod.service: Failed with result 'exit-code'.