Sandboxes paused for more than an hour resume in under a second

A paused sandbox's memory and disk now stay on its server until that server needs the room. Before, they were moved to off-site storage one hour after the pause, and a resume after that took 20 to 50 seconds while they were copied back. A sandbox whose server does need the room still resumes from its off-site copy, with its files and running programs intact.