Bcachefs is not yet upstream - you'll have to build a kernel to use it.
First, check out the bcachefs kernel and tools repositories:
git clone https://evilpiepirate.org/git/bcachefs.git
git clone https://evilpiepirate.org/git/bcachefs-tools.git
Build and install as usual - make sure you enable CONFIG_BCACHEFS_FS
. Then, to
format and mount a single device with the default options, run:
bcachefs format /dev/sda1
mount -t bcachefs /dev/sda1 /mnt
For a multi device filesystem, with sda1 caching sdb1:
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/sda1 for faster access.
See bcachefs format --help
for more options.