Ubuntu 22.04 reboot in order to install updates?

Question

The latest "Software" GUI tool told me that I have to reboot in order to install updates. I pressed "restart and update", It rebooted, installed the updates and rebooted again.

Normally, with update-manager and apt the update is happening while the system is operational, and a reboot (mostly) for kernel updates is required at the end of the process, and at the user convenience time. In other word, it was optimized to not waste the user's valuable time.

This is new to me, and something I've experience with MacOS and Windows before but I never saw anything like it with the majority of the linux distros I've used.

Is this the expected new behavior? Should I not use that "Software" tool and stick to update-manager or apt? This is confusing and somewhat unexpected.

Here is what I've experienced using pictures: Clicked "Restart & Update" and saw this:

After a reboot (BIOS visible) and after some usual kernel messages this process took about 5 minutes to complete, while the system was unusable.

Once it was done, it rebooted again (BIOS visible again) and landed on GRUB:

After a booting, I saw the following notification:

And in the "Software" GUI (after noticeable wait period) I got:

Which seems buggy because of dups, but that's for another post.

Answer 1

The prompt to reboot in order to install updates is a normal prompt that happens sometimes (but infrequently) in Ubuntu 22.04 and later. If you ignore the prompt to reboot in order to install updates Ubuntu will give you a notification to install the same updates when you shutdown the computer with the "install updates" option checkbox checked with a ✓ by default. The entire process of installing updates is streamlined so that it is done automatically without requiring any intervention from the user.

If you don't uncheck the checkbox Ubuntu will start the shutdown process then reboot automatically and install the required updates. During the installation of the updates you will see screens like the 3rd and 4th screenshots in your question. When the installing updates is finished the computer will completely shut down, and the screen go into power saving mode and turn off (for most screens) or it will go blank. All of this is done automatically and requires no intervention from the user.

The next time you boot Ubuntu you will see a screen like the GNU GRUB boot menu screen in the 6th screenshot in your question. If you do nothing at this screen, Ubuntu will keep the preselected *Ubuntu boot option selected and boot automatically to the normal Ubuntu login screen so that you can log in to Ubuntu.

This is a tip for users with screens that have power saving mode that immediately turns off the screen automatically when the computer shuts down. When you shutdown the computer and keep the Install updates option selected by a ✓ by default in the shutdown window, everything that follows will be done automatically, so that you can walk away from the computer when you start the shutdown process and everything after that will be done automatically including turning off the screen.