There is yet-another-Linux-file-system attempt… An initial request for comments (RFC) patch series was sent out this morning for BeamFS. The proposed BeamFS is a Reed-Solomon protected file-system.

BeamFS was born out of the stalled FTRFS proposal earlier this year as a fault-tolerant file-system. FTRFS was short for the Fault-Tolerant Radiation-Robust Filesystem.

BeamFS is described in today’s RFC patch series as:

"beamfs is a block-device filesystem that corrects corrupted bytes in place, on a single device, with no second copy to repair from. Every data block is a capsule of sixteen interleaved RS(255,239) codewords, built on lib/reed_solomon; every read decodes it, and a read the decoder cannot vouch for fails with -EIO instead of returning wrong bytes. Directory blocks, inodes, the allocation bitmap and the superblock carry Reed-Solomon parity as well, and indirect blocks have a parity region of their own. In the default layout 288 bytes of every 4096 (7%) are overhead.

beamfs descends from FTRFS, posted here as an RFC in April. The limits of FTRFS were in its design (threat model, where correction sits, scale, kernel integration), so beamfs is a new filesystem with its own on-disk format, and this is a new thread."

BeamFS goes on to being described for systems where their data is on one storage device and in a radiation prone environment. FTRFS development began with satellite on-board computers in mind as well as systems running in radiotherapy rooms. BeamFS incorporates the feedback of the original FTRFS proposal to hopefully be more acceptable to the upstream Linux kernel and a better design.

Earlier this year due to FTRFS and other new file-system proposals, Linux kernel developers did enact new guidance on allowing new file-systems into the Linux kernel, so we’ll see ultimately what comes of BeamFS for a Linux file-system for radiation-prone environments.