I've been lazy since I've switched to using Macs, but I realise I want to upgrade to OS X 10.8. Well to be safe I had to make a backup for the first time. I've googled the information I want but they didn't seem to help. I read that I needed to buy backup drives at least 2x the size of my hard disk (which would be 1TB) for future backups. But I questioned: what kind of hard disk should I buy? I own an NTFS drive but it has a size of 500GB and 200GB of it is used. I tried to reformat it but I had troubles so I decided to give up and buy a new drive. I think FAT32 would be the best type but I remembered its largest file size being 4GB. So I looked through "All My Files" on my Mac, and the largest file was under 4GB. But Time Machine back-ups my whole Mac, so I've been wondering how large the system files would be? If they are all under 4GB I guess it would be best if I buy FAT32.