Experience of migration from Plone 2.0.5 to Plone 2.1

Ben Calder:

Just thought I'd share my experiences of migration from Plone  2.0.5 to Plone  2.1 - on a site that originally started out at 1.0.1 and has migrated all the way :) - in case my experiences prove useful to others...

On my first couple of attempts I had pre-installed all the products (some custom) that I had on 2.0.5 onto my 2.1 instance and checked that they were working.  This process had worked for me in the past but this time I was getting an odd 'Assertion' error when I ran the migration.

So I tried again from scratch and with another approach.  First, in Plone  2.0.5, I uninstalled my custom skin and also my custom products.  As before I also fixed the AccessRule (module name of 'accessRule' worked fine in  Plone 2.0.5 but in 2.1 meant I couldn't even get into the ZMI - so changed it to match 2.1 - i.e. 'CMFPlone.accessRule').  I then packed the Database and copied data.fs over to a clean install of Plone  2.1, which didn't include the custom products on the file system.

This time I got another error on a dry run of the migration.  Turned out someone had given some unfortunate short names to a couple of pages - 'actions' and 'update' - which goes to show that allowing editing of short names isn't always a good idea.  After renaming these files, and much to my surprise, the migration worked and I could access those pages on my site that didn't depend on my custom products.

So the logical next step was to install these products and see what happened...  they all installed without error and for the most part the content that depended on them was again working correctly, though only after I'd gone into portal_catalog, updated it and restarted Plone.

I suspect that my AT based custom types may not be entirely ready for Plone 2.1 and hence were causing problems with the migration... content from one of them is still throwing a mimeTypes error, though new content created with the same product works fine (fortunately there are few enough instances of this that I can just copy/paste the content across).

So the above process has allowed me to get the site up and running in Plone 2.1 - apparently satisfactorily - and now I just have to double-check all my products to ensure they're properly compatible... which is a small price to pay for the obvious improvements in Plone  2.1 :)

I have to say that the migration tool works exceptionally well - many thanks to those responsible!  Invariably any problems I've had with it have been caused either by my ignorance or by problems I have created...

Cheers

Ben