You can do 30' with an LVL but its going to be big. A few thoughts...
- LVL manufacturers have span table PDF's for their different styles and sizes; go on their website, look up the table PDF, run through the combinations to find which one works for you; there are usually different options for height, thickness and type for a particular span
- that long of a beam is going to be pretty tall, make sure you pick a beam that still provides sufficient ceiling / walk through height
- it'll be heavy, you'll need mechanical help getting it into place; i.e. a crane, hydraulic hoists, jacks, etc
- you'll need to verify that your current end posts and footings can handle the load; putting that much load on 100 year old footings or 3" crap metal posts isn't going to cut it