Today’s Question: Regarding backups, why don’t you recommend the use of RAID drives? I have used one for several years with no issues.
Tim’s Quick Answer: I’m not opposed to RAID drives in general. However, I would never depend on a RAID drive in place of a backup to a separate physical drive.
More Detail: RAID stands for Redundant Array of Independent Disks (or Drives) and refers to what is effectively one housing with two or more drives inside that are interconnected. There are a variety of different RAID implementations, but many of them include redundancy. To oversimplify, you can think of RAID as representing what looks like a single hard drive but where your data is being written to two drives at the same time.
A RAID drive configured for redundant storage provides an efficient solution for a real-time backup of your data, considering that all files you save or update are automatically saved to two different drives. However, those two drives are contained within the same housing, so if that housing is damaged or destroyed you could lose your primary and backup storage all at once.
If you’re using RAID in addition to backing up to another local drive and ideally another remote drive (perhaps via an online backup solution such as Backblaze, https://timgrey.me/cloudbackup), then I have no problem with the use of RAID.
However, I often find that photographers who use a RAID drive think they’re safe, and don’t perform any other backups. I don’t consider this to be a good approach to keeping your photos and other important data safe.
Because of these issues, I simply prefer not to spend the extra money on a RAID drive, and instead put that money into additional backup drives, so I have even greater redundancy. This involves a little more effort to maintain, but I feel that is time worth spent in the interest of a backup workflow that provides greater confidence.