Comment # 11 on bug 1080485 from Martin Wilck

Could you try this:

(https://mirrors.edge.kernel.org/pub/linux/utils/boot/dracut/dracut.html#debugging-dracut)

# mkdir -p /run/initramfs/etc/cmdline.d
# echo "rd.debug rd.break=pre-shutdown rd.break=shutdown" >
/run/initramfs/etc/cmdline.d/debug.conf
# touch /run/initramfs/.need_shutdown

You should now be able to watch better what's going on.

> remove ioctl on system-root failed

Once we're back in the initramfs, shutting down the root LV should work -
unless it's still in use by some process. This is only a real problem if the
situation persists (e.g. because a file system hasn't been unmounted).

bug 1083392 is quite interesting in this respect. It seems to be quite common
that such "remove ioctl" errors occur transiently, and succeed after a few
retries. The error messages are printed nonetheless. If it's just that, we may
want to simply silence the error message and only print a message after the
last retry has failed.