One thought here.. just be wary if you are preserving an archive to last and pass on..    I transferred recordings to CD 20 years ago.. now I am discovering on odd CD's there is distortion. This is CD rot, on some CD's over a period of time the covering layer may well degrade. So as a permanent method of preservation, it is not all it was cracked up to be..   Then eventually DVD's will disappear, and the tech..to play it on. So it's going to be a perennial battle to preserve photographs, recordings, and videos.. Even cloudspace is only good until someone decides to bring the system to a halt and change it in some way!