Is the best way the same was as other grains? Oxygen absorber and mylar bags? I don't see much storing corn meal; should I just store corn instead? Or grow corn then dry it? I can't live without corn meal and need to stash some away!
There is a surplus of mediocrity in this nation and a deficit of bravery.
If you store bolted corn meal it can be kept for quite a while. Bolted means degerminated and is pretty much what all store bought corn meal is. It's similar to refined white flour in the way that it will keep if you pack it with oxygen absorbers or vacuum seal it. The other storage methods such as dry ice or compressed gas will not work well as the texture of the material is too fine.
All of that said I think whole corn is your best bet and is what I do. It stores better, tastes better, and has more nutrition than the degerminated product.
Yes, vacuum sealing or the use of oxygen absorbers will slow down the rate of spoilage, but it won't stop it completely. Three or four years for white flour or bolted corn meal packed that way here in Florida is pretty good. In a cooler storage environment you might get a couple more years perhaps.
I stored white flour and bolted corn meal for a lot of years before I found my first grain mill. So long as you stay on top of the rotation it works fine.
Once you get past about six months worth of food storage though I think you'd really be well served to look at keeping whole grains. I still keep some white flour for those things that I dislike making with whole wheat, but the bulk of what I have now is whole grains.