bcachefs
Nov 2, 2023 · The core of bcachefs is a high performance, low latency b+ tree. Wikipedia covers some of the highlights - large, log structured btree nodes, which enables some novel performance optimizations. As a result, the bcachefs b+ tree is one of the fastest production ordered key value stores around: benchmarks.
Members v2, configurationless tiering - bcachefs
Some of the ideas in bcachefs about how to handle metadata were inspired by Cap'n Proto, which is highly recommended reading - it's a library that does everything we have to do by hand in C, exactly the way we want it.
GettingStarted - bcachefs
bcachefs format /dev/sd[ab]1 \ --foreground_target /dev/sda1 \ --promote_target /dev/sda1 \ --background_target /dev/sdb1 mount -t bcachefs /dev/sda1:/dev/sdb1 /mnt This will configure the filesystem so that writes will be buffered to /dev/sda1 before being written back to /dev/sdb1 in the background, and that hot data will be promoted to /dev ...
IRC - bcachefs
Sep 11, 2023 · IRC. #bcache on oftc.net. Links: FAQ index Last edited Mon Sep 11 14:26:15 2023 Mon Sep 11 14:26:15 2023
FAQ - bcachefs
Sep 27, 2023 · What is bcachefs Bcachefs is an advanced new filesystem for Linux, with an emphasis on reliability and robustness and the complete set of features one would expect from a modern filesystem. How does bcachefs compare to other Linux filesystems like …
Caching, targets, data placement - bcachefs
bcachefs can be configured for writethrough, writeback, and writearound caching, as well as other more specialized setups. The basic operations (and options) to consider are: Where foreground writes go; Where data is moved to in the background; Where data is promoted to on read; Target options and disk labels
Architecture - bcachefs
Jan 7, 2023 · In general, bcache eschews heavyweight transactions in favor of ordering filesystem updates. In this, bcachefs's implementation is in spirit not unlike softupdates - however, since bcachefs is working with logical index updates and not physical disk writes, it works out to be drastically simpler.
RecentChanges - bcachefs
Sep 27, 2023 · add missing etc dir. nixos-generate-config usually sets up etc directory for us but we need it prior to running that command.
Compression - bcachefs
bcachefs compression design: Unlike other filesystems that typically do compression at the block level, bcachefs does compression at the extent level - variable size chunks, up to (by default) 128k.
Roadmap for future work: - bcachefs
bcachefs allocation is bucket based: we allocate an entire bucket, write to it once, and then never rewrite it until the entire bucket is empty and ready to be reused. This maps nicely to both ZNS and SMR zones, which makes supporting both of these directly particularly attractive.