My 4 month old isn't sleeping through the night :(?

When he was 2 months old he used to sleep 5 to 6 hrs at a stretch but as he bacame 3 months old he woke up every 2 to 3 hrs in night and this is continuing till date :( I have tried to feed him well but he goes to sleep after eating 6 oz which I know is not enough for him. I try to give pacifier in the night.Some times it works and sumtime not. Also in nights he drinks very little may be for 5 mins means he is really not much hungry I am really fed up with this and every morning I think of only 1 thing. How to make him sleep through the night. Coz I am woried that this habit will contonue in his childhood even after starting solids. And I'll start his solids after 6 months. Plz give me suggestions on how to feed him full or make him sleep through the night.