---
title: Migrating data from Plone 3.2.1 to Plone 4.0b2
date: 2010-04-23
description: Step-by-step notes on migrating Plone 3.2.1 content to a Plone 4.0b2 buildout using .zexp exports and dual buildouts.
tags:
- plone
- migration
- zodb
- zexp
extra:
  deprecated_reason: Plone 3 and Plone 4 are both EOL; current Plone 6 migration flow is completely different
  deprecated: true
---

These are my notes about the process for migrating data from Plone 3 to Plone 4.

## Intro

One of our customers wanted to renew the look & feel of his website. His
website ran Plone 3.2.1 with a custom skin (one of the first ones made by me,
and one that I'm **not** very proud of).

We decided to do a clean Plone 4 installation with a custom theme and mount a
beta site. The resulting site looks considerably better than the previous one.
We've been updating the site every time a new Plone 4 release comes out to the
public, so at the time of writing of this post, Plone 4 was still in beta2.

## Migrating data

Some considerations:

* Our customer's Plone install didn't have very much customization. We only had a couple of custom themes, CacheFu and `Products.Carousel`.
* CacheFu does not work with Plone 4 (by now).
* `Products.Carousel` works very well with Plone 4 as of version 1.1.
* We wanted to "copy" only selected parts of the old site to the new site. The best way to do this is by exporting Plone content using `.zexp`.

Given the above considerations, these are the steps I took for migrating data
from one site to another:

* Prepare a Plone 3 buildout with a copy of the ZODB of the live site.
* Deactivate/clean/uninstall our custom themes and CacheFu.
* Delete the "leftovers" of the uninstalled themes on `portal_skins`.
* Clear and rebuild the entire catalog (just in case).
* Pack the ZODB (size decreases from 2 GB to 760 MB).
* Upgrade the Plone 3 buildout to Plone 3.3.5.
* Prepare a Plone 4 buildout (in another folder) with a copy of the ZODB of the Plone 3 site.
* Upgrade to Plone 4.

And that's it. Exporting content from the Plone 4 buildout to the new site
works like a charm.

**P.D.** I uploaded a copy of my dual buildout to git: [get it](http://github.com/tzicatl/Plone-3-to-Plone-4-buildout).