i found this link:
http://curmi.com/blog/2008/08/23/time-machine-backup-to-rotating-disks/
this works great for me, even with 3 completely different drives.
1TB external
500 GB external
250 GB 2.5" External
the 1TB drive is my main backup drive
i'm going to leave the 500 GB at my dad's and update it weekly when i'm there.
the 2.5" stays in my safe
http://curmi.com/blog/2008/08/23/time-machine-backup-to-rotating-disks/
this works great for me, even with 3 completely different drives.
1TB external
500 GB external
250 GB 2.5" External
the 1TB drive is my main backup drive
i'm going to leave the 500 GB at my dad's and update it weekly when i'm there.
the 2.5" stays in my safe