If you can mount the drive into another machine running linux, you can probably get to the /images folder and copy your image files.
For the image definitions, host records, and hardware inventory, you’ll have to locate the fog database files. You need to look on the internet/mysql website about how to restore a database from the data files. On the old drive, the data files will be on /var/lib/mysql/ and you may need all of the files or just the ones in the “fog” subfolder. I’m not sure.
If you need help setting up a backup process once you get your FOG server back up, just ask.