sudo apt-get update && sudo apt-get dist-upgrade -y
sudo apt-get install update-manager-core -y
sudo do-release-upgrade
sudo apt-get update && sudo apt-get dist-upgrade -y
sudo do-release-upgrade
good note. Done that way in the past and works.For 99.9% of people, updating Ubuntu is very simple. you just start the updates and follow the questions.
The 0.1% is tricky, but data and settings are usually recoverable. Worst case, you lose the ability to boot into the system, and it becomes near-impossible to fix without going in locally to boot into single mode, or choosing the old kernel to boot from.
Because of the major changes between LTS or Stable versions, migration can cause major issues, especially due to changing kernel and boot systems, as well as merging old and new settings, which might need to be checked individually.
you can leave the system in a permanently damaged state with a mis-configured app, so it's best to have a window open for google-searching what each setting change does, and look at what's changed if you don't quite understand.
If you're okay with the risk,
You can force an update to 18.04 LTS, by first migrating 14.04.6 to 16.04 LTS, then 16.04 to 18.04,
How To Upgrade to Ubuntu 16.04 LTS | DigitalOcean
Ubuntu's next Long Term Support release, version 16.04 (Xenial Xerus), is due to be released on April 21, 2016. This guide explains the upgrade process for systems including (but not limited to) DigitalOcean Droplets running Ubuntu 15.10.www.digitalocean.com
First step is to prep any security/app updates using the current settings, which you should always be keeping updated for security issues, etc (as long as you know what is being updated)
ThenCode:sudo apt-get update && sudo apt-get dist-upgrade -y
it will take about 2-4 hours and download updated apps & services & system files, unpack and replace what is needed, plus ask to merge/update configuration files. Then it will reboot.Code:sudo apt-get install update-manager-core -y sudo do-release-upgrade
Then going from 16.04 LTS, up to 18.04 LTS, repeat the process again, i.e.
How To Upgrade to Ubuntu 18.04 Bionic Beaver | DigitalOcean
<$>[warning] Warning: As with almost any upgrade between major releases of an operating system, this process carries an inherent risk of failure, data loss, or broken software configuration. Comprehensive backups and extensive testing are strongwww.digitalocean.com
ThenCode:sudo apt-get update && sudo apt-get dist-upgrade -y
which will also take another 2-4 hours to download and unpack the newer packages, sic.Code:sudo do-release-upgrade
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