Today’s Question: When you say that your backups make exact copies of your drive, are you saying you are making a mirror copy of the entire drive? In that case you would end up with one compressed file of the entire drive. Is this what you mean?
Tim’s Quick Answer: No, my backups are not compressed, but are instead an exact copy of the primary drive I’m backing up, which makes recovering from a failure remarkably easy.
More Detail: I use GoodSync software (http://timgrey.me/greybackup) to create a synchronized backup of each of my primary external hard drives. With this approach, each backup drive is maintained as an exact copy of the primary drive that is being backed up. That means the entire folder and file structure from the primary drive is created and regularly updated on the backup drive.
In other words, if you were to browse my primary drive and one of the backup drives side-by-side you would see that the backup is an exact match of the primary drive, with no compression or other alterations.
One of the significant advantages of this approach is that if the primary drive fails, I can recover by simply using one of my backup drives in place of the failed drive. No restore process is necessary, because the backup was maintained as an exact match of the primary drive.