Took a full backup of a running mariadb server and restored, but none of the databases are visible
No matter what approach you take there will be at least a brief downtime.

You have M->S, and want G-G-G, correct?

To get another slave from M->S, stop the slave, clone the disk, change server_id, start them up, let replication catch up.  The master does not go down, but you will have S&lt;-M->S.  But that is still not what you need.

I think (but am not sure) that this is the approach.  (There is not a lot of Galera help here, so I will give you more than nothing.)


Optionally keep read access going to your 1 slave.
Stop the Master.
Bootstrap the Master into the first Galera Node.
Stop the Slave.
Turn the Slave into the second Galera Node.
If you have the other Slave do 4&amp;5 to it.  If not give Galera an empty machine and let it build the 3rd node.


Step 6 could be replaced with setting up a "garbd" node -- This is probably a lot faster since no data is needed.  You could do a Step 7 to build a 'real' node and get rid of the garbd.