Based on amazing feedback I got on other related questions I have decided to be brave and try something different, but I am not sure if it can be done. hoping someone has done this and has some insights :-)
Consider the following scenario.
All servers are on the same LAN, through the same Cisco switch and using gigbit ethernet. FYI!
We have a single 2008 R2 file server that hosts all of our department folders/files (e drive) and all of our user profile and user home folders (d drive).
The department folders are shared as 'groups' on the e: drive of that server and set via a logon script (mapping w: to server name \\fileserver\groups share), but there is a domain namespace as well (not sure why since it is not needed).
The user share (for roaming profile) on the d: drive of that server utilizes a domain namespace and that is how each profile is setup, i.e. the profile path and home folder path for each user account in AD points to the domain namespace (\\domainname.org\users\us
I have two new 2012 servers (physical) built and ready to go with all the required roles, etc.
Initially I was merely going to robocopy the data over for the groups share to one of the new 2012 servers (server A) and then repoint the logon script mapping for users which would work fine once they log off and back on.
I was also going to robocopy the users share to a new 2012 server (server B), add it to the existing namespace (right now only hosted by the older 2008 R2 server) and then remove the 2008 r2 existing server from the namespace and that should work fine since the namespace continues (all files are on the new server B and it takes over hosting the namespace) and since the profiles for user accounts in AD point to the domain namespace (\\domainname.org\users\us
file) they wouldn't even notice.
Now the fun/confusing part. I realized that rather than using the two new 2012 servers to each take on one of the shares (groups and users) I could add both of them to both namespaces and then enable replication between them. In theory I would thus have some redundancy if one server goes down then the namespace and associated files still continue. For the groups (department folders/files) there is usually not that much change in the data so standard dfsr replication should handle it, but the users profile might be another story. What happens if a user logs into their PC and downloads their profile from server A, but then logs off saving the profile back to server A (can I even control which one they save to - affinity/cost??) and logs into another PC before server A and server B have a chance to replicate, but server A crashes. Now they are logging into the next PC using only the older profile from server B (the one that still hosts the namespace)? Also what happens when server A comes back online? Or is it better to make a Windows cluster (using the local space on each server - they have identical disks/raid and sizes -https://redmondmag.com/articles/2014/07/14/windows-server-failover-cluster.aspx
) from the two servers and then add the cluster to the namespace to avoid the replication issue?