Hi,
Since https://bugs.debian.org/863290 (2017) the Debian kernel has had a
patch to warn about the use of RAID 5/6 with BTRFS.
That bug mentions "It looks like there's a consensus that such a warning
should live in the kernel rather than userland"
Via [1] and [2] it seems userland did get a warning. It is mentioned in
the kernel documentation (``Documentation/btrfs-man5.rst``) (and [3]
and [4]), but AFAICT users are still not warned by the kernel when
using RAID 5/6.
I stumbled upon this issue when I was (locally) rebasing the Debian kernel
patch for kernel 6.8. I attached my rebased version of the original patch.
(I may have done it completely wrong as I know very little about BTRFS.)
But more importantly, IMO such a warning shouldn't be in a downstream
kernel (Debian), but in the upstream kernel source?
Cheers,
Diederik
[1] https://lore.kernel.org/linux-btrfs/[email protected]/
[2] https://lore.kernel.org/linux-btrfs/bf9594ea55ce40af80548888070427ad97daf78a.1598374255.git.josef@toxicpanda.com/
[3] https://btrfs.readthedocs.io/en/latest/btrfs-man5.html#raid56-status-and-recommended-practices
[4] https://lore.kernel.org/linux-btrfs/[email protected]/