[systemd-devel] fsck, /home, btrfs, multiple partitions/drives, boot failure [Ubuntu 15.04]

[Andrei Borzenkov]

On Thu, May 28, 2015 at 8:46 AM, Andrei Borzenkov <arvidjaar at gmail.com> wrote:
>>> > Apr 24 14:18:41 workstation systemd[1]: Job dev-disk-by\x2duuid-3ff68715\x2d0daa\x2d4e44\x2d8de2\x2d0997f36d8ab6.device/start timed out.
>> >
>> > systemd times out waiting for UUID alias. Neither sda1 nor sdb1 are
>> > present in list of active device units. Please show "udevadm info -q
>> > all -n sda1" and "udevadm info -q all -n sdb1" after boot.
>> >
>>
>> OK, found them in bug report. As expected
>>
>> P: /devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda1
>> E: ID_BTRFS_READY=0
>> E: SYSTEMD_READY=0
>>
>>
>> P: /devices/pci0000:00/0000:00:1f.2/ata2/host1/target1:0:0/1:0:0:0/block/sdb/sdb1
>> E: ID_BTRFS_READY=0
>> E: SYSTEMD_READY=0
>>
>> Something is wrong with scanning for btrfs either in initrd or in
>> running system.
>>
>
>
> Hmm ... looking in kernel, btrfs_scan_one_device tries to open device
> exclusively. If device is already mounted, it will likely fail.

I was wrong here, device is opened by btrfs driver so there should be
no collision here. Still obviously scanning fails (and it fails
actively, setting ID_BTRFS_READY). This needs some debugging on udev
side.