# Pastebin 1L3KWe0j
	=======================
	compute/manager.py
	attach_volume()
	try:
	 volume_api.smart_attach +---> Check and Set DB to attaching atomically
						   ---OR---
					      Return VolumeIsBusy

					      create_export target
					      gather connection_info
				      set DB to attached, deal w/ multi-attach
				 <----------  return connector

	except: #fail or retry

	--------------------
	================   -
	virt/driver.py  <---
	(do actual connection of
	  volume to instance
	   --or fail/exception--
	(return to manager)...
	================
	compute/manager.py
	if failed to connect to instance:
	 volume_api.smart_detach  +-----------> see smart_detach below