Big moves in Linux filesystems as new bcachefs lands and KDE adds support for Apple's APFS

Linux 7.0 is approaching and there's a new version of bcachefs to go with it… as well as green shoots of support for Apple's new disk format. Interesting developments are happening in Linux filesystem land, with a new version of the bcachefs filesystem – and a Linux distro offering support for Apple's APFS disk format. A new version of the next-generation copy-on-write snapshotting GPL filesystem for Linux is out: bcachefs 1.37.0 appeared just yesterday as we write. This release includes support for the forthcoming Linux kernel 7.0. It is expected next month – the latest release candidate, 7.0-rc4, appeared the same day as the new bcachefs release. As we reported last year, bcachefs is now being developed outside of the Linux kernel again, but it can be loaded as a DKMS module. This release has improved erasure coding, faster recovery from unsafe shutdowns, multi-device filesystems are quicker, and more. The notes in the Git commit mention a new version of the bcachefs manual, which creator Kent Overstreet calls its Principles of Operation [PDF] – P.o.O. for short, and the announcement even has a "poo" joke. The PDF version we link to above is the main one on the project home page, but this doesn't seem to have been updated in a while. The release notes say the PoO is now up to 100 pages, while the one on the homepage is just 24 pages long. For information on the latest developments, the bcachefs-tools git repository has more current info. Perhaps Mr Overstreet is making more progress with the aid of the LLM coding assistant we mentioned last month. APFS move COW snapshots are an important feature in modern OSes – the FreeBSD folks are justly proud of their built-in native support for the ZFS filesystem from Solaris. OpenZFS works fine with Linux, but it can't be merged into the Linux kernel because Sun's license is incompatible with the Linux's GPL. For a while, it looked like Apple would also adopt ZFS for macOS, but in the end that didn't happen. Instead, it built its own, APFS, which it launched a decade ago. By default, Linux still can't mount or read APFS volumes. The Reg FOSS desk looked at Asahi Linux 39, and in 2024, Asahi Linux 40 and later Asahi Linux 41. To our surprise, we weren't able to mount our macOS volume. We haven't had time to try it yet, but the March 2026 release of KDE Linux should in principle be able to do just that. It's still in development and only in the alpha-test stage at present, but a new feature this month is APFS support, thanks to Ernesto Fernández's linux-apfs-rw. This too is quite preliminary – it's only up to version 0.3.18, which is the 19th release since the project switched to tagged releases in January 2023. Bcachefs creator insists his custom LLM is female and 'fully conscious' Linux 6.18 arrives as the year's final drop and likely next LTS AlmaLinux gives Btrfs a home after Red Hat kicked it out Fork that: Three alternative kernels show devs don't need Linux KDE Linux is an immutable OS based on Arch Linux, which shares significant aspects of its design with Valve's Steam OS 3. Third party apps are installed using Flatpak – and that's a problem, as Flatpak is mainly aimed at launching GUI apps, and invoking Flatpak apps from the shell is complicated. This release introduces a new container-based system for terminal apps, called Kapsule, which is based around the Incus fork of Canonical's LXD. It won't mount anything on Apple Silicon Macs, mind you. For now, KDE Linux only supports x86-64, and it's not directly targeting Macs at all. Unlike its rival GNOME OS, KDE Linux does explicitly support multiple hypervisors and we hope to return and take a proper look at it soon. ®