I am upgrading TFS 2012 to TFS 2015 in a new hardware with a new configuration. My strategy is to copy the DB and upgrade them and after sometime switch over to the new TFS 2015.
There will be some time between the actual switch over of the TFS from 2012 to 2015, (in my case it will be days). This approach is taken because we cannot have production downtime of the TFS.
Now the time (days) taken, there will be lot of new data inserted in the old TFS 2012 database. How will I migrate the new additional data to the new TFS 2015?
I am having the question because TFS 2015 versus the TFS 2012 there are table changes, this will be taken care by TFS upgrade. But if I want to insert TFS 2012 data to TFS 2015 will there be any issues? or is there a better approach to the upgrade?
You should do a test migration to help you understand how long the upgrade will take.
Once you have this information you will need to take your TFS offline to do the upgrade. This is usually a quick process that can be done in the evening or weekend.
The idea that you can't take any server offline for regular maintenance is a faulty one and is unachievable.
You can't insert data into the database ss this will break tfs.
Syncing data after the fact will prove very difficult and time consuming.