We're in the process of upgrading our servers from
2012R2 and I am currently looking at migrating our SharePoint web/application server (we only have a small deployment so are both on the same box) to 2012. I'm not touching the SharePoint SQL database at all.
I've setup the new
2012R2 server and installed SharePoint Server 2013 onto it, can I simply add this new machine to the SharePoint farm and have the old and the new running side by side for a few days, then remove the old server from the farm?