you ask about the fuel diesel keeps for DECADES provided it WAS STORED PROPERLY.

get a drum pump with a proper water seperating filter and pump it into new drums or a bulk tank. and treat the fuel with some diesel bug treatment it will be fine. it a good idea to have the pump tube shorter than the drum so it doesnt draw the crap from the bottom.

keep the drums in a cool dry place out of the weather and off the ground. bulk tanks should be mounted so they slope to one end so any sediment and moisture will gather there and can be drained off.

the only thing to worry about is if its winter formula diesel or not. winter diesel has additives to stop it gelling in cold weather you can do a dodgy additive with a couple of litres of petrol in 200l of diesel. there are commercial additives too.

why do you think the army use diesel engines in everything because it doesn't deteriorate and why have different fuel if you dont need to. hell the US even stores diesel fuel for Australia yep they did a deal where some of the US strategic fuel reserve is available to Australia