Merge projects from one Jira instance to another Jira instance

[Julia Steak]

We are planning to merge a 10-15 projects from one instance of Jira with another that has 50+ projects. 

I've understood that the best way to do this is to create a full XML backup of source, pre-create empty projects on the target (test) instance, and import projects one-by-one into the target instance. For example, if issues within a project from the source distance have a status that does not exist in the target instance's workflow, a custom workflow needs to be made before import. 

Our source instance has 1,000+ users; is there an easier way to import these users rather than creating each individual user manually? Additionally, many of the users that are tied to issues/projects on our source instance will be inactive on the target instance. What happens when an issue belongs to a user who is active on the source instance but inactive on the target instance? And if there are configuration objects (notification scheme, permission scheme, etc.) on the source instance that do not exist on the target instance, what happens? Do they get set to default?

To anyone who has done this, were there any other issues you ran into? I appreciate the insight. 

[Joe Pitt]

There are many problems importing. Every user, screen, field, etc. has an entry in the database the pointers point to. When you see a user it is pulling the name from the field in the database the pointer is pointing to. It isn't just the text name. The same is for everything else. So you will have duplicate ids pointing to different user, fields, etc. 

[Joe Pitt]

I think there is a tool to help you do this. 

[Julia Steak]

There is an add-on for migrating projects but the price is hefty and not something we're interested in pursuing.