If your purpose is to have data on the two servers be the same, replication is the solution. To perform it without slowing down the server, you must be careful in how you do it.
Probably you will need at least another server to "mirror" the main one and copy data to the local db.
It requests a lot of resources, of course.
For Unix i can't help you out.
If i misunderstood the topic, i m sorry!