Re: "Invalid argument" when mounting a btrfs raid1 filesystem

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Montag, 26. M=C3=A4rz 2012 schrieb Calvin Walton:
> On Mon, 2012-03-26 at 10:51 +0200, Karel Zak wrote:
> > On Sat, Mar 24, 2012 at 06:21:05PM +0000, Hugo Mills wrote:
> > >    As Sadner says, you have to run "btrfs dev scan" before you tr=
y
> > >    to
> > >=20
> > > mount the FS. If you have root on btrfs, this will have to go in =
an
> > > initrd; otherwise, it can go in your initscripts anywhere before
> > > the non-root filesystem mounts.
> > >=20
> > >    Basically, the kernel needs to know which devices hold which
> > >    btrfs
> > >=20
> > > filesystems (organised by UUID) before it tries to mount them. So=
,
> > > there's an ioctl that is used for sending that data to the kernel=
,
> > > and a userspace tool (btrfs dev scan) that enumerates all of the
> > > block devices it can see, looks for a btrfs superblock on them,
> > > and tells the kernel.
> > =20
> >  Please, move all this logic to udev rules where we already scans a=
ll
> >  devices. It's really bad to scan all device more than once. We spe=
nt
> >  years to fix this problem for LVM, I don't think that btrfs has to
> >  repeat the same mistakes.
>=20
> Oh, this is already possible to do with udev rules, quite easily. In
> fact, dracut ships with the appropriate udev rules, which it uses to
> initialize btrfs filesystems in the initramfs:
>=20
> http://git.kernel.org/?p=3Dboot/dracut/dracut.git;a=3Dblob;f=3Dmodule=
s.d/90bt
> rfs/80-btrfs.rules;hb=3DHEAD
>=20
> which would be suitable with minor modifications for use in a system
> udev installation as well.

I reported this for Debian long time ago as:

please support raid configurations automatically
http://bugs.debian.org/bug=3D634658

I will be forwarding your mail to the bug report as to suggest this ude=
v=20
based solution.

I has also been reported as:

btrfs-tools: add initramfs boot and hook scripts
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=3D559710

please provide non-initramfs-tools integration
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=3D585568

Thanks,
--=20
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7
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