On-disk format change beckons for brave early adopters of Bcachefs
New versions of the two leading next-generations filesystems are coming: both OpenZFS 2.2.3, and some time afterwards, an improved bcachefs.
Kernel 6.7 only appeared last month and as we wrote at the time, it finally included the next-gen bcachefs filesystem. We say finally because it didn't make it into 2023's kernel 6.5, just as it didn't make it in 2022 when we looked at its features and what it promised to deliver.
Well, now, Torvalds and his army of techie termites are labouring away on kernel 6.8, and lead developer Kent Overstreet just submitted a revised bcachefs which makes some improvements to the version in 6.7. The patch notes in the link describe what this version changes, focussing on how it handles disk space accounting. It notes that the old way was simple and fast, but "limited," noting "lack of scalability", and that it was "a pain to extend." There's some more information about this in the official project roadmap.