From Mandriva 2010 MySQL 5.5.9, to Ubuntu 12.04 LTS MySQL 5.5.31.
We copied the 400GB Database with Rsync. It took some 7 hours to migrate, but after that it was just to fire up mySQL in the new server and change DNS addresses to point to the new server. In the old server we set up a MySQL proxy to reroute inbound traffic to the new server just in case. The transition was extremely smooth not a single problem until a mail arrived
‘Is there a problem with the Data Warehouse? ’
When our application calls the Data Warehouse we receive ‘4.0 protocol is not supported ’, please help.
WTF, this was not something I expected by upgrading MySQL some patch levels of the same release. After we have rummaged the building we found an old derelict Dell server in the basement. It turned out to be an old Mandrake 8.1 Linux running on the machine for years, and those who knew of the server setup had long since left. We (wisely) decided not to touch this server, instead we started up a copy of the database in version 5.5.9 and rerouted the obsolete application(s) to this DB instance. Next we will virtualize a copy of this Linux system and then upgrade it to more modern Linux probably a Mageia Linux.