How can I crawl/index only 5 site collections without losing the crawled/indexed other site collections?

Question

I am using SP 2010 and FAST Search. I have a contentsource for the webapplication url "intranet.myCompany.com". This is working, but very slow. I would like to create some content source for only 5 site collections:

intranet.myCompany.com/sites/sitecollection1
intranet.myCompany.com/sites/sitecollection2
intranet.myCompany.com/sites/sitecollection3
intranet.myCompany.com/sites/sitecollection4
intranet.myCompany.com/sites/sitecollection5

Is this possible or do I need to remove the existing content source? I do not want to lose all the current crawled/indexed site collections (crawled already by the current content source)

Answer 1

I would create a Scope that has these site collections listed as include rules. Then there is no need to remove the existing content source, the scope is just a subset of that index.