Working from memory (we're in the middle of planning a similar upgrade), this isn't necessarily very complicated.

1. Upgrade to the last 4.7 release--that's mostly security stuff and some minor (any?) table changes. You need to do that in all cases, even if you don't go on to 5.x (but you probably want 5.x soon, since 6.0 is imminent.)
2. Make sure that there are updates to all of the modules you need, or modules to which you can migrate, to meet your needs.
3. Upgrade to the current 5.x . (Is there an "upgrade to 5.0" step? I don't think so, but I could be wrong. You'll want to do this on a test/dev site first, as some themes are likely to break, depending on what you have customized how.

There seems to be some decent documentation on the drupal.org site. Look in the "tutorials" page of the "handbook" section. Here's a useful Introduction to Upgrading: http://drupal.org/upgrade/tutorial-introduction

ari
On 10/15/07, Daniel Carrera < daniel.carrera@zmsl.com> wrote:
Hello,

I have a production website that runs on Drupal 4.7. Should I move it to
Drupal 5.2?

I'm concerned that migrating might be difficult, might be work, or might
cause downtime for my users. On the other hand, I'm concerned about
staying with an old software version that might become unsupported in
the future, and that migration might be more difficult later.

My Drupal 4.7 site has several modules added on and I figure that these
might not all work in Drupal 5. My understanding is that backwards
compatibility is not a development goal for Drupal. So perhaps the best
way to "migrate" is to essentially re-do the website from scratch and
then copy all the content from the 4.7 site.

I'm generally happy with Drupal 4.7. Is there any page that briefly
explains what's new and exciting in Drupal 5 that might make one want to
move to it?

Any help would be appreciated.

Cheers,
Daniel.
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