Potato flakes, pearls or dehydrated slices are all types of potatoes that you can store in your food storage. Potato flakes can be bought at the LDS cannery and have a shelf life of 30 years when packaged in #10 cans. Potato Pearls have a limited shelf life due to added oils and can only be bought in 28 oz packages.
Other types of dehydrated potatoes such as slices, chunks and hash browns can be bought at Costco, Sam’s Club and online at various food storage sites. Check these products when buying to make sure there are no added oils. Dehydrated potatoes with added oils will have a limited shelf life and will not work for your long term storage.
Most potato flakes or instant mashed potatoes that are bought in local grocery stores have added flavors and oils. These will be great for your 3 months supply, but not for your long term storage.