Migrating to new sharepoint and merging new changes in content database

Question

We need to migrate from WSS 3.0 to SharePoint 2013, as I understand there is no direct way to do this in single step, so we need to migrate first to 2010, then to 2013. As long as our content database is ~50gb (we have only one content database), I'm afraid that doing this by simple detach/attach will cause too long downtime.
Does SharePoint support this scenario, if yes, how:

1. we make backup of WSS 3.0 content database also leave WSS 3.0 server running
2. we restore backup from step 1 to intermediary server, upgrade it to 2010
3. we restore backup from step 2 to new server, upgrade it to 2013
4. now interesting part - can we somehow merge changes, that were done in WSS 3.0 during upgrade time into upgraded database in new servers?

Or there is completely different way to do this while having minimal downtime (read-only mode for content database is not an option, as having it read-only would be pretty much the same as downtime for us).

Answer 1

There is no way to merge the content from old version to new other then moving the DB.

The best answer to your question is, it is not possible with OOTB but you can get it from 3rd party tools i.e Sharegate or Metalogix.

3rd party tools will give you option to directly migrate from 2003 to 2013.

With 50 Gb, I don't think you need a long down time. If

• 2010 farm already set up
• 2013 farm already set up
• test migration from 3.0 to 2010 and from 2010 to 2013.

If all above steps went well then with 50GB I don't see more than 2 hours of total migration time.