Is all our memory actually residing solely in the akashic records, or just copied to that location? If so, does that include short-term as well as long-term memory?

It is a copy of the memory. The actual memory is within the pool of consciousness that is a soul extension. The true repository of memory is within that soul expression constituting the human persona you feel of as being yourself. The akashic record is a repository of everything that happens, and it is keyed to your memory as well because this is an important reference for you to know what the impact has been on the universe, in addition to the recollections you may have within your consciousness of all that has happened, and your thoughts about it. What is in the akashic records is the sum total of your existence rendered as an energetic signature. Your memory is your perception and experiencing of your life, and that is unique and personal to you and obviously of tremendous value and high-level need, to know who you are, where you came from, where you are going based on your plans and hopes, and so on. So the two are separate and distinct—each with a purpose and a function and important implications for your place in the universe and how things evolve.