The Western Digital MyBook Duo external drive internally consists of two 4 TB drives and is configured as a RAID 1 drive. Thus it becomes only a 4 TB drive but it automatically makes a backup copy of whatever I store on the drive.

Only after I am sure that the RAW photo files have successfully been stored on the PORTFOLIO drive, I return the CF card to my camera and format it. I only format my cards in camera… not with a computer.

Periodically, I will make use of another hard drive to make another backup of my files. This hard drive is then stored in my safe deposit box.

Note:

When I am on the road, I travel with two USB powered portable hard disk drives. I will copy the RAW photos from the CF card(s) to both of these drives, verify each and then format the CF card in my camera. Better safe than sorry.