The Ubuntu 20.04 MDB Enterprise 4.4 DEB file does not install a conf file at /etc/mongod.conf, but expects that file to be there in the /lib/systemd/system/mongod.service file it does install. This means that a user installing MDB per our live instructions, in the same way they installed MDB 4.2, will not be able to start the MDB 4.4 binary they just installed without some sysadmin knowledge / SO research / troubleshooting.

Also noticed:

• This DEB file does not create /var/lib/mongo, but does create /var/log/mongodb. Per 4.2 ( and this part of the live 4.4 instructions, here) both dirs are expected to be created via this DEB file. My error: Debian-based uses default dbpath of /var/lib/mongodb.
• Ubuntu 20.04 complains of MDB service file using legacy PID file location. Just FYI. See repro.

Repro steps for MDB 4.4 Ubuntu 20.04 attached in ubuntu20-mising-conf-file-repro.

I suspect this applies to Community as well, and possibly to other DEB files, but do not have the time to presently test any further. Please extend research for this issue to the other DEB files for 4.4.