I'm starting this new thread in follow-up of the few questions I posted here
Briefly put:
I have a B3 with squeeze in full raid (so not only /home) which I like to see upgraded to jessie still in full raid.
Reason:
I use my B3 almost exclusively for hosting an Owncloud server. Todays client versions no longer officially support the server version currently running, which freaks out my 'most important user' as it shows up in big red line of text each time you synchronize. Todays server versions require more recent version of Debian. And last but not least: it's just good practice to upgrade now and then and be able to get (security) updates.
Things considered:
Since my B3 is in full RAID it's no longer a 'standard' device. To make the full raid work some fiddling had to be done in u-boot variables. See MouettE's wiki and here. That said, I have always been a bit anxious on upgrading (main reason why I'm still on squeeze).
Advantage:
Since my B3 is in full RAID I can disconnect the e-SATA, attempt/do the upgrade on the B3 with a broken diskarray. If something goes wrong: I shutdown, swap the disks from S1 and B3, startup, see if everything works as expected, shutdown again. Plug-in the S1 with the now messed up disk in it, startup, and have the RAID rebuilt. Should be easy peasy

The options:
This seems the most straight-forward solution at first. Today however, I still have all the excito packages, but that shouldn't be an issue, I can still remove them. What bothers me more here is that, since I like to move onwards to Jessie, I need to upgrade twice. Squeeze => Wheezy => Jessie. Each extra step involving maybe extra risks to mess up. In the end I still have a B3 with some original excito residu leftovers. Not that I have something against excito, but I just like to have it cleanif you already removed all the excito packages from your B3 I would recommend doing a manual upgrade of your B3 ( apt-get dist-upgrade ) that way you'll keep your data and configuration. I can help you with that and provide the steps

I'm considering this approach. Afterwards I can install 'whatever' I want without having things running I don't need/use in the end. Owncloud still running today is version 5.something (read: old and outdated) So it would be better to re-install this also and along side MySQL. Like I said: clean.If you wish to format and use the new image, the best path would be to boot the rescue system (remove the image param in install.ini) ; format and mount your raid device, untar the image on it, mount and edit the /etc/fstab to reflect the new root location, unmount and restart the b3. It should work and at least you should keep your RAID configuration. Never tested though, I don't have RAID anymore at home.
On the other hand: option 1 would be a great test and learning curve to get things done whilst saving the most of the settings etc...
If anyone has some suggestions, information, knowledge to share: feel free.
I'll be updating this thread/editing this post just to create some kind of howto for others interested.