XMP Sidecar files-worst case senario

[AdrianL]

I set up a test disaster and this is what I discovered.  I pretended that my computer was destroyed, my backups unreadable, and the only recourse was my one archive disk stored offsite.  I attached my offsite archive disk to my laptop, double clicked on the LR_photos.lrcat file and found it corrupted.  The image files along with the related XMP sidecar files were however intact.   I created a new Lightroom Library, went to FILE and selected Import From Disk.  Selected Add Photos To Catalog Without Moving.  After the import, the images were present, all editing, flags, keywords were present.  Only the History list and the Collections were missing.  I was able to RESET an image to its original condition when I first imported it in the original library.  
No, the disaster did not happen, but if it does, I know how to fix the worst senario.  One more thing-- I now have 2 archive disks stored offsite in 2 different locations.  Thank you Seth and Michael.

[frugal]

Don't have a solution for you, but this does raise a very important point that wasn't mentioned in the video; verifying your backup strategy. It's much better to find an issue like this, and resolve it, when you're not depending on your backup to restore everything.

The biggest mistake computer users make is assuming they don't need a backup (or deciding it's too much work). I'd argue the 2nd biggest is assuming that your backup strategy is doing what you want without testing it.