From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Steigerwald Subject: Re: "Invalid argument" when mounting a btrfs raid1 filesystem Date: Mon, 9 Apr 2012 13:58:16 +0200 Message-ID: <201204091358.17229.Martin@lichtvoll.de> References: <87vclt99tg.fsf@falma.de> <20120326085134.GK2040@x2.net.home> <1332774058.22830.2.camel@ayu> (sfid-20120326_183334_799404_40348DC5) Mime-Version: 1.0 Content-Type: Text/Plain; charset=utf-8 Cc: Calvin Walton , Karel Zak , Hugo Mills , Christoph Groth To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <1332774058.22830.2.camel@ayu> List-ID: 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 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html