An update on bcachefs
An update on bcachefs
Posted May 31, 2018 21:45 UTC (Thu) by Wol (subscriber, #4433)In reply to: An update on bcachefs by Cyberax
Parent article: An update on bcachefs
To be fair, fixing the write hole is tricky - in fact it seems to me that it is inherent and unavoidable in a simple raid 5 implementation.
Even md raid has only just fixed it, with the addition of a journal (a feature that might still be experimental). The journal is intended primarily as an optimisation, flushing updates to SSD before saving them to the full raid on spinning rust. It fixes the write hole almost as a side-effect.
(Note, understanding the journal is on my to-do list, I need to learn more about it before I can document it ... :-)
Cheers,
Wol