Can I do a Silent or Unattended Release Upgrade?

Solution 1:

The following command upgrades to the new stable release without prompts:

do-release-upgrade -f DistUpgradeViewNonInteractive

The following command upgrades to the current development release without prompts:

do-release-upgrade -d -f DistUpgradeViewNonInteractive

I haven't tested it, but it seems it just performs the default action when a question arises. It also times out any scripts if they hang for too long.

You might have to do use dpkg-reconfigure afterwards if you are unhappy with the configuration of certain packages, but most of the time you should be ok.

Source: http://awaseroot.wordpress.com/2012/04/29/ubuntu-release-upgrade-fully-automatic-non-interactive-upgrade/ . In the link there are also other ways to do this.

Solution 2:

To confirm what Thomas Ward states in his answer and contradict the accepted answer, do-release-upgrade -d -f DistUpgradeViewNonInteractive DOES NOT WORK.

In fact at the very first prompt it broke my 16.04 to 18.04 test partition broken and I had to reclone it. This is where the script freezes:

Setting up mount (2.31.1-0.4ubuntu3) ...
Setting up systemd (237-3ubuntu10) ...
Installing new version of config file /etc/pam.d/systemd-user ...
Installing new version of config file /etc/systemd/journald.conf ...

Configuration file '/etc/systemd/logind.conf'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ?  Your options are:
    Y or I  : install the package maintainer's version
    N or O  : keep your currently-installed version
      D     : show the differences between the versions
      Z     : start a shell to examine the situation
 The default action is to keep your current version.
*** logind.conf (Y/I/N/O/D/Z) [default=N] ? y

Y
CRASHED... NOTHING HAPPENS NOW... WILL KILL AND RESTART WITHOUT -f OPTION...

Due to Input Inhibitors neither reboot nor shutdown will work after killing the script. You have to do a cold shutdown (hold power button ~ 10 seconds).

Thank goodness this was a 16.04 clone upgrade and not on the real 16.04 partition.

To make life even more interesting a new 898 MB partition was added to my NVMe SSD and my regular partitions shifted:

$ lsdrv
NAME        FSTYPE  LABEL                  MOUNTPOINT          SIZE MODEL

nvme0n1                                                        477G Samsung SSD 960 PRO 512G
├─nvme0n1p5 ntfs                                               858M 
├─nvme0n1p3                                                     16M 
├─nvme0n1p1 ntfs                                               450M 
├─nvme0n1p8 ntfs    Shared_WSL+Linux       /mnt/e                9G 
├─nvme0n1p6 ext4    Ubuntu18.04                               23.7G 
├─nvme0n1p4 ntfs    NVMe_Win10             /mnt/c            390.4G 
├─nvme0n1p2 vfat                           /boot/efi            99M 
├─nvme0n1p9 swap    Linux Swap             [SWAP]              7.9G 
└─nvme0n1p7 ext4    NVMe_Ubuntu_16.0       /                  44.6G 

• nvme0n1p5 used to be where my Ubuntu 16.04 partition resided but now it is on nvme0n1p7
• nvme0n1p8 used to be where my 18.04 test partition resided but now it is on nvme0n1p8

NOTE: I also upgraded Windows 10 from Build 1709 to Build 1803 this afternoon so it is possible that it created the new 898 MB nvme0n1p5 partition in ntfs format.