I guess I should clarify, my question is more along the lines of shifting my install from a tomcat install of DM-5.5 to a .deb install of 5.8 (by doing 5.6 then to 5.8). Does the tomcat install place things in a different place than the debian installer? If I do not have too many customizations in place, would it be enough to install a new install of 5.8 via .deb and then import my data into it?

The main differences between the plain zip and the debian package are:

• deb package uses a more standard directory structure
  
• it has dependency on 3rd-party packages needed by Nuxeo
  
• it can help set up PostgreSQL
  

If you want to switch from the zip to the deb package, the main steps are:

• install the deb package
  
• stop the deb-based nuxeo with /etc/init.d/nuxeo stop
  
• move your current nuxeo.conf to /etc/nuxeo/nuxeo.conf
  
• either move your data dir to /var/lib/nuxeo/data or change nuxeo.data.dir in your nuxeo.conf to point at your current data dir

Thank you for that clarification. So if I am to understand correctly, the two could actually reside side by side on the same machine, as long as they each had their own database cluster, and data store, right?

Basically, I am going to be doing an OS upgrade to Wheezy 7.2, and then a migration from 5.5 to 5.6, and then 5.6 to 5.8 (which we will probably stick with for the life of the LTS).

Would I just tell it to use the same database as 5.5 / 5.6? I need to upgrade PostgreSQL from 8.4 to 9.1 as well. What is the right order to upgrade components? If I use the .deb, would it pull down postgres9.1 or so, and then install a fresh nuxeo database, which I would then have to overwrite with my old?

There are a few more things that could conflict, like the listening address+port, but basically yes, you could run both the zip distribution and the deb package on the same machine as long as those conflicts are resolved.

The deb package will pull "postgresql >=8.4" so as long as your postgresql install was with the meta "postgresql" package and not the "postgresql-8.4" package the db version upgrade should be transparent when you do your distribution upgrade. Otherwise it will just be a matter of player with the pg_upgradecluster command.

Your Nuxeo data is basically present in two locations: the database, and the nuxeo.data.dir for file data, which defaults to nxserver/data when using the zip but should really be moved out of the distribution directory for any kind of production use (and if you're in cluster mode, the repositories.binaries.store).
To be safe, you should backup those before trying to upgrade, but as long as your nuxeo.conf points to those same locations, the upgrade should be relatively painless.

Thank you so much! I cannot remember if I explicitly installed postgresql by number or meta-package. I will have to look into it.