After upgrading Lubuntu from version 17.10 to 18.04, I noticed booting slowed down significantly. I hid the splash screen and noticed the booting hung on trying to run /scripts/local-premount. Specifically, on the message Begin: Running /scripts/local-premount. It turned out to have something to do with initramfs and having an encrypted home directory. I do not know, and do not particularly care, about all the details, but essentially initramfs is trying to find a device that does not exist.

To make initramfs not hold up the booting process, edit the file /etc/initramfs-tools/conf.d/resume. In it, you will see something like

RESUME=UUID=someuuid

The mentioned UUID does not correspond to any of your devices. To fix the slow boot issue, change the contents of this file to

RESUME=none

After having done so, run the following command to make initramfs aware of the changes you made. Your next reboot should be nice and quick again.

sudo update-initramfs -u

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