Item — HN Reader

> It is actually hard for me to imagine why would one use that "single" mode in practice.

Yes, this is what I'm starting to discover also. Because single mode is the default I assumed for the last 9 months that it would provide similar guarantees as MergerFS. But that was my incorrect assumption. As a result of this experiment I'm investigating MergerFS and I will likely switch from multi-disk btrfs to an array of single-disk btrfs under MergerFS.

edit: actually I'm not sure I would convert my array to raid0 because the speeds I'm getting are okay. 20% of data is better than nothing. I did the same with raid0 data profile and only inlined extent files were readable

I used to run a manual version of mergerfs (before it existed) - a bunch of disks, files were manually copied into one of the disks, and scripts maintained "tree of symlinks" which pointed to all the files. Later on, I needed to export this as SMB, so I've added de-referencing overlayfs to generate a single huge disk, and exported that. Worked pretty well and while manual placing required some effort, I could keep similar files together.

Later on I ended up buying few more disks and creating large ZFS RAID6 array.. And it "just works" now, no need for custom scripts.