You can try getting special foot to avoid hair balls, but in the end, hair balls are natural. Cats groom, and the hair agitates the stomach then poof, hairball. It shows your cat is a good and detailed groomer. Hairballs=good grooming cat
It's normal for longhairs to have hairballs.
He's 3 years, and only 2 hairballs. Seems pretty normal by what my knowledge knows.
I read up that hairballs are okay every few months, but once they get down to more then once a month, you should start to worry and move to a different diet to try and see if you can stop the hairballs from getting too often.
My kitten had a hairball once, I think. She's 1 year old, a mix of a Siberian and other things(deduced from physical aspects, no confirmation). I flea comb her every now and then when I get the time, and have a brush for her(though it's useless. She's pretty self-sufficient)
If he starts to have frequent hairballs, like twice or more a month, then I'd worry, but even at once a month, I myself would get annoyed and buy different food to combat the hairballs. Hairballs are not nice, but they are natural and are not something to worry about when once or twice a year.
Here's a site on some small info;
http://pets.webmd.com/cats/guide/what-t ... ls-in-cats