Systemd unmounting filesystems

Symptoms

You may see that filesystems are being unmounted occasionally on your server. You may see entries like the following in /var/log/messages.

Aug 26 03:47:52 host systemd: Unit home.mount is bound to inactive unit dev-sdc.device. Stopping, too.
Aug 26 03:47:52 host systemd: Unmounting /home...

Description 

This may be due to Systemd unmounting the filesystem. This can occur if a filesystem is mounted after boot. systemd-fstab-generator generates units for each mounted filesystem at boot time. If the filesystem is not mounted at boot, the unit will not be generated and system may try to unmount the filesystem.

Workaround

After mounting any filesystem, the following command should be run to update Systemd about the change.

systemctl daemon-reload

If the filesystem was supposed to be mounted during boot, you will want to investigate if there were any issues mounting it.