SO I currently have a TC that I use as a backup source, however I have recently been getting a message that tells me TC will purge old backups to make room for new ones. This is confusing to me as my macbook hard drive is only 160GB and I have a 500GB TC that has 210GB available. Any reason I am getting this message? A second question is about storage. My macbook internal drive is getting full as I have a 1 year old son and taking more and more pictures everyday. I recently began shooting more in Raw format and the files are starting to take up more and more space fast. I would like to move these to an external hard drive to free up space on my macbook drive. My idea is to have this connected to the TC so I don't have to carry around the drive all the time on my lap. My fear is that this method is unsecure as this would be the only drive with the files. Is there a way, using some sort of software I guess, Time Machine would be ideal, to have 2 external drives connected to the TC, one for storage and another as a clone or mirrored drive so if the main fails I would still have a back up copy? If that sounds confusing I am sorry. I appreciate the help.