Package: bcachefs-tools
Version: 24+really1.3.4-2
Severity: normal
I have / as a multi-device bcachefs filesystem (two different SSDs,
with replicas=1). Booting from it was an, well, interesting endeavor :-)
It seems the following must be done in Debian before this Just Works(TM):
- /etc/fstab must contain the UUID, not a colon-separated list of
devices, or systemd will wait forever (because it doesn't understand
the syntax; I believe this is an upstream issue).
- Likewise, root= on the kernel command line must contain the UUID
or the initramfs scripts will wait on some colon-separated device that does
not (and will never) exist. grub-mkconfig must be updated to write root=
_back_ from a colon-separated device list to a UUID; I don't know if there
is already some kind of support for UUID-roots, but I think so.
As of today, it fails with:
/usr/sbin/grub-probe: error: failed to get canonical path of
`/dev/nvme1n1p1:/dev/dm-2'.
- initramfs must contain mount.bcachefs, since that is the only thing
that knows how to probe a UUID into multiple devices. This means that
the Rust parts needs to be built again, too (see #1060256).
- The initramfs scripts attempt to rewrite UUID=<foo> _back_ to a
single /dev device through probing, and give that to mount. It needs
to avoid doing so for (multi-device) bcachefs filesystems, or they
will never mount since they contain too few devices.
- The GRUB command line must be rw, not ro; mounting with -o remount,rw
gives: “bcachefs: bch2_parse_mount_opts() Invalid mount option errors:
invalid selection”. I don't know if this is an upstream issue or if
this is just considered a bug in our setup.
I don't have patches for any of this, unfortunately; I've just finagled
it by hand in my local system. But it's at least a laundry list :-)
/* Steinar */
