This started as a comment to Alex Kunz's post on DNG and Backups. After commenting on Alex's post, I decided to write a post detailing my backup strategy.
Comment on Alex’s Post
It is interesting to see the perspective of a professional photographer when it comes to backup and file formats. As a cyber-security professional my perspective is different.
For me, standard file formats are more important because I can expect broad support for that format and longevity. With DNG I have all the originating RAW data plus all my edits in one file. I think proprietary file formats can lead to vendor lock-in and being left stranded if the vendor changes format or abandons the format. And as long as the software supports it, I can edit my DNG (and any changes) in any photo editor.
I am more concerned with my ability to recover from data loss than how much storage my files consume or how long backup takes. And I test my backups. I have friends who are professional photographers and I know for a fact they never test their back-ups. I have a few times, deleted everything from my hard drives and restored them from back to test my backup strategy.
Current Backup Strategy
All of the images are stored in an Adobe Lightroom Catalogue on a 5 TB external hard drive. The Lightroom catalogue consumes about 846.41 GB of disk space. CrashPlan’s backup software continuously backup backups my images (encrypted) to CrashPlan’s cloud service and to a separate 5TB external hard drive. A real-time file watcher checks for new files and file updates, and backs up changes every 15 minutes by default.
If the drive holding my catalogue fails I can buy a new drive and restore from the local backup. If both hard drives fail, I can purchase new drives, and I can recover from the CrashPlan cloud.
Settings for Adobe Lightroom are also backed-up to the local CrashPlan disk and cloud, as well as via Apple’s Time Machine software.
If I suffer catastrophic failure — a fire in my house consumes the computer and all attached hard drives — I am confident that I could recover my entire system in a few days.
I know some people baulk at spending over a hundred dollars on big drives but that cost is nothing compared to the value of the images. Only an idiot puts cheap tyres on a car carrying their kids.