Merging two confluence instances
Asked by Rahul Aich [Nagra]:

Hi

Our organisation has recently decided to merge two confluence instances that we have. I would like to know what are the challenges involved in the activity.

A few specific questions:

- Does both confluence instances need to be on same versions? Our source confluence is on 4.3 and target on 5.3

- Does both instances need to have the same plugins installed? on Our source we have around 70 odd plugins (free + paid),

- The target confluence is crowd authenticated but our source confluence is not. Will it cause any issues?

- Our source confluence has local directory autheitication but target has LDAP authentication. How do we manage this?

- Any other challenges you may think of?

Rahul


Answers:
author: Thomas Wendel
body: Hi Rahul,

Merging two instances of Confluence is best done with exporting all spaces of your source Confluence separately and importing them to the target Confluence ([Exporting Confluence Pages and Spaces to XML](https://confluence.atlassian.com/display/DOC/Exporting+Confluence+Pages+and+Spaces+to+XML) / [Restoring a Space](https://confluence.atlassian.com/display/DOC/Restoring+a+Space)).
> - Does both confluence instances need to be on same versions? Our source confluence is on 4.3 and target on 5.3

Yes, both instances have to be of the same major version ([You cannot restore to a different major Confluence version](https://confluence.atlassian.com/display/DOC/Restoring+a+Space#RestoringaSpace-Note2:YoucannotrestoretoadifferentmajorConfluenceversion)). So the first step would be to update your source Confluence to 5.3. This has other advantages as well, see further points below.
> - Does both instances need to have the same plugins installed? on Our source we have around 70 odd plugins (free + paid),

That's a lot of plugins! However, not all of them might be really "User-installed add-ons". Whenever an administrator updates a plugin that is actually a bundled Confluence plugin, it appears under "User-installed". After upgrading your source Confluence, some of those plugins might disappear from the list.

Here is what you should do:

* Update all plugins of your source Confluence.
* Consider deinstalling some plugins. Do you really need all of those plugins, especially the paid ones? Generally the fewer plug-ins you have, the easier it will be to maintain your installation.
* Make sure all of the plugins you really need are available for the target version 5.3, using the [Update Check](https://confluence.atlassian.com/display/UPM/Checking+Add-on+Compatibility+with+Application+Updates).
* Install all the plugins you really need on the target Confluence as well.

> - The target confluence is crowd authenticated but our source confluence is not. Will it cause any issues?

Generally this will not cause any trouble. Users that do not exist on the target Confluence will be created, when you import the spaces (make sure the local directory is enabled on the target Confluence!). Do the user names match on both installations? Otherwise some users might end up with two different user accounts. So after you upgraded the source Confluence to 5.3 it is actually possible to [change user names](https://confluence.atlassian.com/display/DOC/Changing+Usernames). Do this before you export all spaces.
> - Our source confluence has local directory autheitication but target has LDAP authentication. How do we manage this?

Make sure the local directory is enabled on the target Confluence. Users that are not in your LDAP directory will be created there. You might want to manage merged users in LDAP as well. You can do this before or after you import all spaces.

Keep in mind that you might have to upgrade your licenses for the target Confluence and Crowd if the total amount of users surpass the amount of the licensed ones.
> - Any other challenges you may think of?

This whole procedure can not be done in 5 minutes and will most likely not work the very first time. In order to make sure everything works as expected, to keep the downtime as short as possible and not end up with an unusable system:

* **Try all steps on a test system first!** Make sure you take notes of every step!
* **Backup everything!** Be sure you know how to restore the system in case something goes wrong.
* Test everything throughly after the test and the productive migration!

I hope this helps. The whole procedure needs a bit of planning but it can be done.

Cheers,  
Thomas

comments: author: marshall_craig
body: Any suggestions for User References and Personal Spaces?


author: mparsley
body: So, there's no way to do a merge of two instances using the full site backup?


author: Snorre Selmer
body: No. If you import a full site backup into Confluence, you wipe out ***all*** data already stored in the target install.


author: RambanamP
body: you only answerd for most of your questions, check this doc

<https://confluence.atlassian.com/display/DOC/Restoring+a+Space>


Tags: confluence-administration

migration

xml