Monday, April 15, 2024
 Popular · Latest · Hot · Upcoming
rated 0 times [  2] [ 0]  / answers: 1 / hits: 2485  / 1 Year ago, sat, april 15, 2023, 9:22:08

I have a UEFI laptop with two disks, /dev/sda and /dev/sdb.
Ubuntu 16.04 is installed on /dev/sdb. There is already an ext4 partition of /dev/sda, but I want anything there to be overwritten.
I wish to install Ubuntu 20.04 on /dev/sda, such that:
1) During a transition period, I can boot from either Ubuntu 16.04 or Ubuntu 20.04
2) After a transition period, I will delete Ubuntu 16.04 from /dev/sdb
3) I don't have to physically disconnect /dev/sdb before doing the installation

I boot the computer from a USB with the Ubuntu 20.04 image on it. When I get to the screen asking for the installation type:

Q1) I presume I should choose "Something else", because installing Ubuntu 20.04 alongside 16.04 will install it on /dev/sdb, which I do not want. Is this correct?

Q2) After selecting "Something else", do I choose /dev/sda or do I choose /dev/sda1 (which already has the ext4 filesystem on it)?

Q3) On the same screen, where I am asked for the device for the boot loader installation, the options are:
/dev/sdb2 Ubuntu 16.04 LTS
Given my goals as described above, which option should I choose?

More From » boot


  • I suggest that you start by unplugging /dev/sdb. That way there is no risk that you will touch it during the installation.

  • After that it is straightforward to install Ubuntu 20.04 LTS into /dev/sda. Reboot and check that it works.

  • Next shutdown and connect /dev/sdb.

  • Boot into /dev/sda and from there run

    sudo update-grub

    It should identify the operating system in /dev/sdb and add a grub menuentry for it.

  • When you no longer want the old operating system you can remove it (by erasing it or unplugging the drive). Then run

    sudo update-grub

    and the menuentry for it will be removed.

[#3669] Sunday, April 16, 2023, 1 Year  [reply] [flag answer]
Only authorized users can answer the question. Please sign in first, or register a free account.

Total Points: 396
Total Questions: 90
Total Answers: 106

Location: Saint Lucia
Member since Sun, Sep 5, 2021
3 Years ago
biryanrownies questions
Wed, Sep 7, 22, 18:13, 2 Years ago
Fri, Dec 3, 21, 02:50, 2 Years ago
Sat, Feb 12, 22, 16:02, 2 Years ago