Global Cinder settings are not seen by driver configuration

[Michael Denny]

Global Cinder settings are not seen by driver configuration.

For example create volume from image needs to enable multipath, it has to be set in each group instead of one global setting.

I can't just turn on the global setting in cinder.conf
#use_multipath_for_image_xfer=false
use_multipath_for_image_xfer=true

I have to enable it in each driver

enabled_backends=emc, 3par

[emc]
use_multipath_for_image_xfer=true
volume_driver = cinder.volume.drivers.emc.emc_smis_fc.EMCSMISFCDriver
volume_backend_name=emc

[3par]
use_multipath_for_image_xfer=true
volume_driver=cinder.volume.drivers.san.hp.hp_3par_fc.HP3PARFCDriver
volume_backend_name=3parfc

[Walt Boring (walter-boring)]

This is the cause of the dangling lun issue as reported in bug 1325717.

When you attach a LUN to the kernel and it's attached via multiple paths, multipath daemon must be installed, and the cinder.conf setting for user_multipath_for_image_xfer must be set to True.

[Michael Denny (michael-denny)]

Multipath daemon is running as expected, at a minimum documentation is needed.
If 3PAR Fiber Channel is configured and multipath is enabled then use_multipath_for_image_xfer=true is required.
Currently use_multipath_for_image_xfer=true is documented in Global section of cinder conf sample we should add this to the 3PAR driver section. Or maybe there is a way we could handle this automatically in the 3PARFC driver.

[Michael Denny (michael-denny)]

https://review.openstack.org/#/c/195770/

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/openstack-manuals 15.0.0 release.