I am dealing with three domains. One of which I control, the other two have External type non-transitive trust relationships with ours. Our domain is at Server 2003 functional level and I am not sure about the other two domains, although it is very likely that they are at that level or earlier; so probably not at Server 2008 or above. We need to do a schema upgrade so we can migrate our DC's to 2008 and beyond. (Also we're interested in the Linux integration options that become available with the 2008 schema.) Our dcdiag and netdiag reports are clean.
Although it's clear from the whitepapers that describe 2008 that the trust relationship model is different in 2008, no one anywhere is talking about what kind of prep work or coordination needs to happen when we upgrade our schema. Will it break our trusts? Will we need to tweak something? Do we need to make sure some configuration, like functional levels or FSMO roles are arranged properly?
Any advice or info you can point me to would greatly appreciated.