sarge to etch and mysql
 

Hi,

I'm going to update my debian 3.1 to etch 4.0
What about mysql?
There will be some problems with existent databases (mail authentication, ftp user, etc..)?
Many thanks.

I am compelled to say once again, never upgrade when you can install from scratch. You will avoid lots of problems. You could install Etch on a new partition or disk and port your SQL data over to the new system directly from the Sarge partition. You will have the latest SQL binaries without any untidy leftovers. Heed my words. Upgrading ONLY leads to heartache and despair.

While this is true for some distros I've tried, Debian handles really well release upgrades. Downgrades, although not official supported, are also possible.
For installing from scratch, you'll have to backup, export,.. depends where your datas are stored.

This page might help:
http://wiki.debian.org/Sarge2EtchUpgrade