I have an external hard drive hooked up to my iMac and have been using Time machine for backups. What I am wanting to do is take this hard drive to my dads house as a secondary backup in case of a fire,etc. at my house, and hookup a new primary hard drive to the iMac at my house. Periodically, I will need to backup what's on my primary drive to the secondary drive in case anything ever happens to the one at home so that I always have two copies. A few questions: 1. Is it best to delete all the time machine backups except 1, before taking the hard drive to my dads? Can I just delete the old backups in finder or is there a better way? 2. When later backing up the primary hard drive to the secondary one, do I just copy the most recent time machine backup each time? If there is a good resource for this type of thing, that would be great. I have searched everywhere and haven't had much luck with Time machine specific solutions to what I'm wanting to do. Thanks in advance.