Is there a filesystem that keep track of all filesystem modification without snapshot?

Question

I am interested in btrfs and I start understanding and loving it COW process.

But what I understand is that I need to do snapshots to keep track of all modifications done on file. What happen when there are multiples modifications between 2 snapshots? I guess I just have the last state at snapshot time.

Is there a way with btrfs or another filesystem to keep track of all modifications on files (including moving files)? IIRC DEC had such features keeping all files backups with ~ extension then ~~ then ~~~ and so on.

Answer 1

Log-structured file systems provide this, albeit not in the same way as VMS. You can think of them as a circular buffer, remembering previous versions as long as there’s room for them.

On Linux, one such file system is NILFS2; it provides continuous snapshots, and user-configurable garbage collection. The latter means that when a volume fills up, the user can configure which snapshots are deleted — so you could have many recent snapshots, and less frequent snapshots as you go back into the past, instead of the more obvious “delete the oldest snapshots” one might expect from a circular buffer.