I just installed a new 1TB system drive, of which 872 GB are currently available, and installed Snow Leopard on it. I also installed a new 1TB backup drive, which I formatted in Mac OS Extended (Journaled). I pointed Time Machine to the backup drive and politely asked it to go to work. I got this error message:
Time Machine could not complete the backup. This backup is too large for the backup disk. The backup requires 2.39 TB but only 999.20 GB are available.
Why does the backup require 2.39 TB for a 1TB drive? Is this new to Snow Leopard? My previous drives, target and source, were the same size under Leopard (500 GB), and I never had any trouble with Time Machine. Must the backup drive now be 2.5 times the size of the source drive? Do I have to go to Carbon Copy Cloner?
Mac Pro 2x3.2 GHz Quad-Core Intel Xeon, OS 10.6.6, 18 GB ram; 2x1TB, 2x2TB internal drives