[Pkg-zope-developers] Migrating an existing plone 2.0.4 site (ie. stable) to 2.1 (ie. testing) is brutal!

[Dustin Harriman]

Hi all,

I've had a happy plone 2.0.4 website running using stock Debian sarge
plone packages for a year or two.  I recently decided to upgrade plone to
2.1, using the current Debian testing packages.  The installation of the
newer Debian packages went fine, but I wanted to warn everybody with a
tale of woe about how difficult such a migration will be when it comes to
upgrading all your existing data within your existing Plone 2.0.4 site to
be Plone 2.1-compatible.

I unsucessfully tried to follow the upgrading advice on the Plone site here:
http://plone.org/documentation/faq/upgrade-plone

I posted my migration difficulties there as a comment, which say (FYI):


Title: "this migration advice will not help Debian users"
Posted by dustin at 2005-10-12 12:32 AM

"Hi. I'm trying to upgrade to plone 2.1 from 2.0.4, using stock debian
packages of both Zope and Plone.

In Debian sarge/stable, Zope 2.6.4 and Plone 2.0.4 go together, coming as
standard Debian packages. In order to get Plone 2.1, one must switch to
getting Debian's testing packages instead of stable ones. Then one gets
the coupling of zope 2.8 and plone 2.1. But the Data.fs from zope 2.6.4 is
completely unusable in zope 2.8! When starting the Zope 2.8 instance using
the old Data.fs, python pegs the CPU forever (after 2 hours it was still
chugging) and zope allows no connections to the ZMI. Normally it would
take about 10 seconds to start allowing connections to the ZMI.

To get around this, I tried making a clean Zope 2.8 instance, after first
exporting the Plone site as a .zexp file (under the old system), and
importing it into 2.8. In this way I was hoping to press this magical
"Upgrade" button mentioned above. The import failed! Similarily, importing
so much as one html document/page from Plone 2.0.4 (using a .zexp file)
also fails, since the internal formatting has changed for documents/pages
going from 2.0.4 to 2.1.

So be warned, 2.0.4 -> 2.1 seems like a small change in version of Plone,
but it's huge considering the need by many users for a newer version of
Zope which can leave you with an unusable Data.fs. If you need to also
upgrade Zope in addition to Plone, prepare for a profoundly brutal
migration. The instructions above assume you do not need to upgrade Zope,
only Plone.

My current approach is to export all html files using the FTP server, then
I'll use a couple of python scripts to change all the internal Plone
2.0.4-style headers to be Plone 2.1-compatible, then FTP them back into
the new instance."


Regards,

Dustin Harriman
http://annexia.ca