Restore mysql databases from files

[dam034]

Hi everyone,

a few days ago I lost my server. The motherboard no longer worked, but the hdd worked normally. The old server was ubuntu 16.04.

So I installed ubuntu 22.04 server on a new computer, and I want to restore mysql databases from /etc/mysql folder.

Is there a way?

Thanks

[TheFu]

/etc/mysql is just for MySQL settings. The actual DBMS files are under /var/llib/mysql (usually). BTW, there have been huge mySQL changes over the years, so you'll need to look up the migration steps to get from the version you had to the version you will be running. That's what release notes are all about. READ THEM!

With the release of 24.04 yesterday, people will begin practicing the production server migrations from 22.04 to 24.04 ... practicing ... since they don't want any data corruption or data loss, but going back to 16.04 is so long ago that most of us have forgotten any issues. Heck, we stopped using MySQL and switched to MariaDB sometime between 2026 and 2018, so there are other migrations you may want to consider.

Today, the default DBMS is MariaDB and MySQL is deprecated for a number of years on Ubuntu.

Sometimes the best method is to perform a mysqldump to get text files for the entire DB, then restore them into a new system with a new DBMS engine.

[dam034]

I also have the folder /var/llb/mysql.

All the tables have three files: frm, myd and myi.

Is there a way to restore the tables?

Thanks

[TheFu]

A way? Yes.

Install 16.04 somewhere, place the DB on that system in the expected location, open the DB using normal DBMS commands, then use mysqldump to create a backup for everything in the DB. All tables, views, triggers, constraints, external functions, everything. Take that dump to the new system and use the opposite of mysqldump to recreate the DB under the new OS.

It might be easiest to create a virtual machine with 16.04 on the new hardware. It doesn't need to be a huge VM, just large enough to run the DB for 1 user and do the mysqldump.

https://linuxize.com/post/how-to-bac...ith-mysqldump/ shows how to backup and restore.
MySQL 5.x --> 8.x migration: https://dba.stackexchange.com/questi...-via-mysqldump
Google will find lots of examples, if you need others.

[dam034]

So I created a VM with ubuntu 16.04, installed via tasksel the lamp server.

Now, I only have to copy the files in the folder? Or is there some other to do?

Thanks