I'm a ranch owner so I have tanks for my diesel for off-road for my tractor and on road for my trucks.
I have stored diesel for years with no problems.
One thing you have to watch out for is sweating. If you get any water vapor in a non sealed tank (and you will from the air) then that can grow bad things. Kind of weird to me that things can live in a very small amount of water in a pool of diesel.
It's a good idea to put some Biocide in the tank if you are going to store diesel for a very long time (6 months or longer).
Also make sure your filters are up to snuff and you will be good to go. I filter twice. One on my feed tank and one on my truck. I know you can't do this for your truck but I have never had any problems.
My neighbor bought a 10,000 gallon load real cheap years ago. He told me he sucked on that tank for over 10 years!