Thanks! https://blog.botux.fr/fr/2015/02/installation-ubuntu-utopic-14-10-encryption-manuelle-lvm-on-luks/ is wrong towards the end.
Nothing special is needed in /etc/default/grub and /etc/initramfs- tools/conf.d/cryptroot shall not be created. Simply put CryptDisk UUID=xxxxxxxx none luks in your /etc/crypttab and the warning is gone. It would be cool if the installer setup all that automatically. It works in full disk but not in dual boot. You can close this bug. ** Changed in: cryptsetup (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1804314 Title: Wrong WARNING Option 'hash' missing in crypttab To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1804314/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs