I have a very large content database & need to split it. Is it possible to split a content database within a site collection? or I need to create a new site collection?
It is not possible to have multiple content databases service a single site collection. You would need to find a way to actually migrate the content from your one site collection to multiple site collections.
In situations where there is a single site collection that holds a bunch of sub-sites, such as in an Intranet scenario, I would look at moving the sub-site content to individual site collections for those departments.
In situations where you are doing large scale document management, I would look to use something like the Content Organizer to move the content to a series of back end site collections and content databases and then provide easy search and content roll up features to make the experience as easy and transparent as possible.
To handle the content moves required for either scenario you could either:
- Move the content manually
- Write custom code or powershell scripts to move the content from source to destination
- Use a third party migration tool that can move the content from source to destination