Backup A Networked Drive to Another Networked Drive with Time Machine

[bwicklund]

I just purchased an Airport Extreme with the intension of attaching a USB hard drive for Time Machine backups. I've already set this up, but I also have a second hard drive running into the Airport Extreme through a USB hub with all of my music on it. I would like to backup this music drive to the first hard drive, too, but don't know how to configure this.

Can someone please help?

Also, is there any trick to speeding up the initial switch to a wireless hard drive back up, because it is moving very slowly.

Thanks