source: sipes/modules_contrib/cck/UPGRADE.txt @ 6e81fb4

================================================================
UPDATING FROM VERSION 4.7 to 6.x
================================================================

THERE IS NO DIRECT UPGRADE PATH FROM 4.7 TO 6.x!! FIRST UPGRADE
YOUR DATABASE FROM 4.7 TO THE LATEST 5.x VERSION, THEN UPGRADE
TO 6.x.

ALWAYS BACKUP YOUR DATABASE BEFORE UPGRADING!

1) While 4.7 is still installed, upload the latest 4.7 version of
   all the CCK files, go to update.php, and run all possible
   updates for the Content module and all field modules.

2) Install Drupal version 5. Once it is running, upload and install
   the latest 5.x versions of all CCK modules, go to update.php and
   run all possible updates.

Jump to the instructions for updating from version 5.x to 6.x.

================================================================
UPDATING FROM VERSION 5.x to 6.x
================================================================

YOU MUST RUN ALL POSSIBLE UPDATES TO YOUR DATABASE IN 5.x USING
THE LATEST 5.x CODE, BEFORE UPGRADING FROM 5.x to 6.x.

ALWAYS BACKUP YOUR DATABASE BEFORE UPGRADING!

1) Before upgrading to 6.x, upload the latest 5.x versions of all
   CCK modules, go to update.php and run all possible updates.

2) Disable all CCK modules and remove them from the modules folder
   before upgrading.

3) Install Drupal version 6. Leave all contributed modules out of
   the modules folder until core modules are up and running.
   Set your administration theme to a core theme like Garland until
   everything has been updated to help ensure you don't encounter
   theme-related problems accessing the administration area.

4) Once core is running, upload and install the latest 6.x versions 
   of ONLY CCK CORE FILES (the ones in the tarball on the CCK
   project page). Enable them, then go to update.php and run all 
   possible updates. DO NOT add any other CCK modules to the 
   modules folder until the core CCK files are updated and working 
   correctly.

5) After updating CCK core modules, you may get messages saying that
   some updates failed and that you need to run update.php again.
   If you get messages like that, keep re-running update.php until
   you get no more messages.

6) Once the core CCK modules are updated and working correctly,
   add other CCK modules to the modules folder, enable them,
   and run update.php. For best results, do this one module at a
   time so you can tell immediately if any of them create problems
   without letting those problems interfere with other updates.


Your database should now be ready to run in CCK version 6.x

================================================================

The 4.7 to 5.x steps are necessary because of significant changes 
in the database structure between the 4.7 and 6.x versions. These changes
make it extremely difficult to create an automatic upgrade path that
will work reliably in every possible situation.

The extra steps in the 5.x to 6.x upgrade are because all modules
in the modules folder are automatically updated in Drupal 6, even if they
are not enabled. That means that modules that rely on core CCK may try
to run their updates even if core CCK is not enabled, and contributed
CCK modules that have broken updates will have their broken updates
run even if they are not enabled.

A number of updates are dependent on other updates and won't work
until previous updates are finished or specific modules are enabled,
so you may get messages that other modules need to be enabled or that
update.php needs to be re-run, and you need to follow those instructions
until all the updates complete.

Taking extra time during the upgrade by leaving modules out of the
modules folder altogether until you are ready to enable and update them
should reduce or eliminate update problems.