dracut fails to build bootable initramfs on fc22

[Alex]

Hi,

>> I have a fc22 system that's been working fine and now for some reason
>> kernel updates result in an unbootable system. It appears to be
>> related to dracut failing to build a proper initramfs image.
>>
>> I have a default initramfs from 4.0.4-300 that works fine, but using
>> dracut to build a new initramfs during a kernel update or building it
>> manually fails. Rebooting the system only makes it to "Reached target
>> Basic System" where it just stops.
>>
>> I really have no idea how to proceed, so I'd really appreciate any
>> ideas for troubleshooting this further.
>
> In the GRUB menu, press e to edit the default boot entry. Find the
> linux16 or linuxefi line, scroll to the end and remove rhgb quiet. Add
> systemd.log_level=debug rd.shell and then either control-x or F10 to
> boot. You should get a ton more debugging information, and when
> there's a failure you'll get a shell. There you can mount some volume
> like a USB stick somewhere like /mnt or if that doesn't exist then use
> /sysroot

I'm at the point where I have a dracut shell and have inserted a USB
stick formatted with ext2. The device is detected, but apparently no
device has been assigned to it.

Looking in /dev, only my hard disks are there among the block devices.

Any idea how to mount a USB stick in dracut? Interestingly, I can't
find anything about this problem with Google.

Thanks,
Alex