Storage in Gloucester

http://www.dainton.com/caravan-storage-in-gloucester.html

http://www.gloscarastore.co.uk/

just 2 from Google, loads more on there.

If your still looking I use Court Farm in Twigworth.  There is also one out towards Badgeworth by the hump backed bridge and a storage compound down Bristol Road by the Ford dealers.  Other than that It's quite difficult to find one close to the City.