I left my MacBook Pro backing up to an external drive using SuperDuper only to wake up and find that the progress was where I had left it. I had used my hot-corners that put my display to sleep also requiring a password on wake-up when I left it backing up overnight.
The file copy continued after I logged back on in the morning and the hard drive began flashing showing activity. Copying resumed but this time I turned off my display using the brightness keys instead of "locking." I noticed the same thing backing up with Backblaze, and also copying from one external to the other.
What's going on it seems like file operations aren't permitted when a user is logged in but the sign-on screen is active?
Using Mac OS X Mavericks. Power Options: Computer Sleep is set to Never & Display Sleep is at 10 minutes. Put hard disks to sleep when possible is unchecked. Require Password set to after 4hrs in Security.