I have an external hard drive with all my old iMac backups on which go back for about 6 months. Now, I have a MBPr and I want to use the same drive for my MBP backups. The issue I have is that my drive is 1TB and my old backups take up about 700GB of that drive, despite the actual used space on my iMac only being 450GB.
What I'd like to do is to remove all but the latest backup from my iMac (which should be 450GB) which leaves me with 550GB for my MBP backup.
What's the best way to do this? Obviously I can't just delete the old backup folders apart from the last as they're all symlinked.