Jbofs – explicit file placement across independent disks

Hey all,

I created `jbofs` ("Just Bunch of File Systems") as an experiment to workaround some recurring issues I have run into with suprising filesystem performance.

My use case is storing large media (think pcaps, or movie files), where some hierarchal organization is still useful.

Whether it’s NFS mounts (and caches), ZFS, or RAID (mis)configurations, I’ve run into surprising(ly bad) performance on many occasions. Doubtless this is largely user error, but it can be hard to diagnose what went wrong, and I’ve resorted to things like copying a file to `/tmp` or some other local mount with a simple ext4/XFS filesystem that I understand. When I see r/w happening at 200MB/s but know that 66GB/s is possible[1], it can be quite disheartening

I’ve wanted something dead simple which peels back the curtains and provides minimal abstraction (and overhead) atop raw block devices. I’ve messed around with FUSE a bit, and did some simple configuration experiments on my machine (a workstation), but came back to wanting less, not more. I did do some RTFM with immediate alternatives[2], but could have missed something obvious -- let me know!

As a compromise to avoid implementing my own filesystems, I built this atop existing filesystems.

The idea is pretty simple -- copy files to separate disks/filesystems, and maintain a unified “symlink” view to the various underlying disks. Avoid magic and complication where possible. Keep strict filesystem conventions.

Of course, this is not a filesystem. Maybe that’s a bad thing -- which is one thing I’m trying to figure out with this experiment.

If you have experience using anything like the other filesystems or similar stuff, would love to get your feedback, and especially thoughts about why this symlink thing is not the way to go!

Lastly, thanks for taking the time to look at this!

[1] https://tanelpoder.com/posts/11m-iops-with-10-ssds-on-amd-th...

[2] https://github.com/aozgaa/jbofs/blob/main/docs/comparison.md