3x to 4.1.x Migration Question

[axman505]

We will soon be moving a redhat 9.0 box to redhat enterprise 4 AS. The question is, what is the best way to migrate the 3.23 mysql databases to 4.1 which comes stock with rhel4?

The normal migration path is to upgrade from 3.23 -> 4.0x -> 4.1.x.

My initial thought was to perform the migration on a different box with the above path.

But i was thinking, what happens if you try to load mysql 3.23 dump files into mysql 4.1? Will it convert those upon loading?

Thoughts are welcome, thanks!

 

[dalchri]

My method for upgrading is to transfer all the metadata and data using SQL. I use the import/export functionality in MySQL-Front so I don't have to write the SQL.

This does require two databases, the old one and the new version and it does take awhile to transfer the data. However, I find it to be less involved, more reliable, and less error prone than following the lengthy upgrade steps that MySQL uses. Discarding the lengthy process of two upgrades (3.x -> 4.0.x and 4.0.x -> 4.1.x) might make this an attractive alternative for you.

This has the added benefit of compacting your data files.

One last thing to look out for are your permissions. You can transfer those files in the mysql database but the newer versions have additional fields that you will probably need to fill in to have permissions work properly. In this case, I just added all the permissions from scratch since they aren't too involved in my db.

 

[ericbrunson]

Since fedora comes with 3.something installed by default, I regularly upgrade simply be installing the 4.1.x rpms from MySQL.com.

That being said, I would definitely do a full dump of all databases adn I would backup the datadir. If I was really paranoid, I would copy the database to a second machine and do the upgrade there just to see it work, but then again, I've done this a dozen times and I'm not paranoid.

 

[axman505]

What i tried in testing was to install the base mysql 3 rpm, import my databases .. then i upgraded to the latest rpms .. and everything seemed to work correctly.

I am assuming the rpms take care of any upgrading of tables that needs to happen. Is this correct?

 

[ericbrunson]

The rpms have well thought out post-install scripts that handle the administrivia required to migrate through releases. Pay attention to the messages printed out when you upgrade the server package and understand the ramifications.