Hi Daniel,
Thank you for all those suggestions. I think it is a bit early to set up such an agreement. We just started the first team and we will need to figure out how to best work between the system hackers and blog hackers.
Since we don't have big requirements, the blogs are a nice testing ground for this cooperation. Right now, my suggested guideline would be: Anything OS related is the system hackers' responsibility and anything application/service related the blog hackers' responsibility. That line may become a bit more blurred in the future and then we need to decide how to continue from there. Right now, the differentiation is pretty clear though, especially if we use Wordpress from upstream.
I am a big fan of planning things ahead of time, but at this time, I wouldn't know what to plan. We have a running setup that needs to be migrated. The result will probably not be the ideal solution yet, but a step to make the blogs reliable again. For the time being, the blog hackers team need to find out the necessary steps for the migration. Generally, we are talking about exporting the database and the files, and then testing upgrade paths on the new system. There may be additional in-between steps that we will need to determine first. For example, this morning, the MySQL dump did not run cleanly and that means the database needs to be fixed first. There are probably other things we need to figure out along the way.
After that, we will have a better overview of what we have and what we think we should have. This will enable us to make good decisions about the future of the platform in regards to technology. That may be the time to set up the kind of service agreement you suggested.
For the time being, I am happy to just contact Albert quickly to say "Hey, would you please have a look at this.". That is also a more efficient use of ressources with limited man-power right now.
Happy hacking! Florian