Comment # 1 on bug 1052770 from Ladislav Slez�k

That's strange, according to the log the setting passed for the
/sys/block/sr0/queue/scheduler file, but failed for
/sys/block/vda/queue/scheduler.

Could you manually try setting the scheduler? E.g.

  cat /sys/block/vda/queue/scheduler
  echo noop > /sys/block/vda/queue/scheduler
  cat /sys/block/vda/queue/scheduler

Does that work?

Or could you try the same from Ruby IRB?

   irb
   File.read("/sys/block/vda/queue/scheduler")
   File.write("/sys/block/vda/queue/scheduler", "noop")
   File.read("/sys/block/vda/queue/scheduler")