How can I upgrade an Ubuntu Linode that has reached EOL without hurting my WordPress configuration?

Hey there, this is a pretty delicate situation! While it's understandable to want to just run the APT command to upgrade your current Ubuntu version, I would absolutely not recommend this - please, please don't do it!

Upgrading your infrastructure step by step requires time, preparation, trial/error and patience. To set expectations, please be advised that you may encounter issues with dependencies down the line when reconfiguring your WP infrastructure to work with the latest version of Ubuntu. I am hoping, however, that the very general suggestions I provide here will make upgrading your infrastructure a smoother process for you. I can only provide general suggestions as I do not know what the current versions of Ubuntu, WordPress, Nginx, PHP or MySQL that you are currently running.

To start things off, I will say this again because it is super important:

Please proceed with caution and be sure to back up your current working infrastructure in case you need to revert along the way, especially your MySQL database.

Below are some helpful resources on backing up your infrastructure:

Resources on backing up your Linode server:

• How to use The Linode Backup service
• How to Create an Image of your Linode
• How Copy your Disk over SSH

Resources on backing up your CMS, Database and Services:

• How to Back Up Your WordPress Site
• How to utilize mysqldump to Back Up MySQL
• How to back up your Nginx configuration

Additional thoughts on upgrading WordPress:

If you are running a very old WordPress version, some of your plugins may not work after your upgrade, potentially including older themes you may be using with your site. So you might find that you may need to investigate new themes and plugins to use, but your WordPress infrastructure will be much more secure once you handle those updates!

Once you have made backup copies of your entire server, as well as separate backups of your service configurations, databases and your WordPress site configuration, you will be enabled to move forward with your upgrade.

Suggested steps for Upgrading your Infrastructure:

1) Create a new Ubuntu 18.04 LTS Linode, and enable backups on it right away if that is feasible for you.

2) On this Linode, install WordPress using their 5-minute install guide.

• When you install WordPress, ensure that the following versions of PHP, MySQL and Nginx are also installed:
• PHP 7.3 or higher
• MySQL version 5.6 or higher
• Nginx version 1.16.1 or higher

3) At this point, you will want to check that your WordPress install works as expected. You will hopefully just see an empty WordPress site page using the default theme. Once you have gotten the default install with all upgraded packages working, I would suggest that you take a Backup Snapshot of your entire upgraded Linode in case you need to restore it.

4) You will now want to attempt to import the backups that you saved of your WordPress site, MySQL database and Nginx configuration. You can use some of the resources I included earlier in this guide, backtracking the steps you took there. This is the part where you may encounter error messages, so be sure to track them and troubleshoot as necessary.

As I am unsure of the exact versions that of WordPress, PHP, MySQL and Nginx that you were originally upgrading from, I am similarly unsure of what you will need to troubleshoot ahead of time.

Please feel free to reply to this thread with any error messages you encounter and the Linode Community will help you overcome them!