Journaling file system for HDD
 

My first post:

Hello community,

Is there a way to use JFFS2 (or other journaling file system) on an HDD? I'm looking for a file system feature that doesn't overwrite previously written data on an HDD.

Reason I'm asking is I'd like to use the capacity of the HDD as a log of all written activity, with the ability to retrieve old files. i.e. all writes to the HDD would be sequential.

What you're describing is a log structured f/s, not a journalling f/s.
I don't know of a Linux f/s that'll do what you want.