Is this for long term emergency food storage?
You can buy freeze dried staples (rice, pasta, vegetables, meat) that are sealed in a can with oxygen absorbers that have a 25 year shelf life.
If you are going to store your rice for years then oxygen and moister absorbers will only help reduce the chance of a ruined batch when you need it for an emergency. Plus you can get 100 packets for like $9 on amazon. Very little cost for some extra insurance.
I also dont trust do-it-at-home vacuum storage for that long. I've had stuff in vacuum sealed bags in a cabinet only to find that they leaked a few months later.
That's been my experience. Consumer brand vacuum sealers are great for preventing freezer burn and leaking. It definitely reduces the space needed for storage of pretty much anything you package.
But, the seals aren't "industrial strength." The pump can only extract most of the air, not all of it. The sealer doesn't prevent air from entering the bag while it starts sealing. And the seal itself is just good enough to close the bag. Sometimes there are gaps in the seal, and I have to seal it a second time 1/8th inch offset from the first to get a full seal.
Best method for using the sealer for emergency food is to rotate your stock. Eat it as needed, and replace it with freshly sealed, new food. That way you'll now if the process works for you. Results might indicate the need for a more professional/commercial model sealer/bags.