On 08/05/2012 06:45 AM, Tom Gundersen wrote: > On Aug 5, 2012 6:04 AM, "C Anthony Risinger" <anthony@xxxxxxx> wrote: >> On Sat, Aug 4, 2012 at 7:53 AM, Jackson Alley <toomanymirrors@xxxxxxxxx> > wrote: >>> I've rebooted and confirmed the udev rule I found does not resolve the >>> issue. I don't believe the problem lies with mkinitcpio as I'm not using >>> a root btrfs system but rather in the init scripts >>> ( > https://projects.archlinux.org/initscripts.git/commit/?id=13ca7f028ac775773a6685966d0faeee5cc55a9d > ). >>> I've attached the boot log and dmesg output. >>> dmesg: http://pastebin.com/PxfnYgAm >>> boot log: http://pastebin.com/Pg9xY4u5 >> yeah i didn't think mkinitcpio was involved but you said it was >> throwing an error about a missing btrfs hook, even though you have no >> hook defined ... so i asked. >> >> AFIAK the FS module is not loaded automatically until mount time -- >> dmesg shows the module being loaded at that time, not when scanned. >> dracut loads the module just prior to calling `device scan`: >> >> > http://git.kernel.org/?p=boot/dracut/dracut.git;a=blob;f=modules.d/90btrfs/80-btrfs.rules;h=e74f9a6af647e465d9367e95b37aef2e57ddfdbe;hb=HEAD >> ... and since scanning requires /dev/btrfs-control, which is not >> created until the btrfs module is loaded, the module MUST be loaded to >> properly register the device. i was able to confirm that `btrfs >> device scan` DOES NOT automatically load the required `btrfs` module. >> >> your dmesg shows required devices loading at this time: >> >> [ 4.058562] sd 9:0:0:0: [sde] 976773168 512-byte logical blocks: >> (500 GB/465 GiB) >> >> ... but the module is not loaded until after all devices fire: >> >> [ 4.171028] Btrfs loaded >> >> ... therefore probably nothing was registered, and thus a few seconds >> later you see: >> >> [ 6.081051] btrfs: failed to read the system array on sde1 >> >> ... try this (tested for one device, unverified for more): >> >> # cat /usr/lib/udev/rules.d/70-btrfs.rules >> ACTION!="remove", SUBSYSTEM=="block", ENV{ID_FS_TYPE}=="btrfs", >> RUN+="/sbin/modprobe btrfs", RUN+="/usr/bin/btrfs device scan >> $env{DEVNAME}" > This makes a lot of sense. Please verify. > > Tom Thanks you guys, this worked with slight modification: $ cat /etc/udev/rules.d/60-btrfs.rules ACTION!="remove", SUBSYSTEM=="block", ENV{ID_FS_TYPE}=="btrfs", RUN+="/sbin/modprobe btrfs", RUN+="/sbin/btrfs device scan $env{DEVNAME}" Jackson
