https://github.com/openstack/os-brick/commit/8d919696a9f1b1361f00aac7032647b... might be relevent although from a nova point of view you shoudl set https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.vol... to true if you want to enable multipath for volumes in general and https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.vol... if you want to enforece its usage. there are some other multip path partemr like https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.ise... for iSER volume. but i dont belive nova has any options related to for NVMEoF backends. that os-brick change seam to be adressign the issue you reported below by removign the dep on multipathd but it depend on this cinder change too https://review.opendev.org/c/openstack/cinder/+/934011 https://bugs.launchpad.net/os-brick/+bug/2085013 all fo this happend in the last 7 months or so so it should be in 2025.1 unfortunetly i do not see any documeation change related to this to explain how to properly configure this end to end On 25/07/2025 13:00, Vincent Godin wrote:
Hello guys,
Openstack: 2025.1 OS: Ubuntu 24.04
We are having trouble configuring multipath on a NetApp backend using NVMe over TCP. After reading numerous articles on this issue, we concluded that it was necessary to operate in native multipath mode, which is enabled by default on Ubuntu 24.04, and that it is no longer necessary to keep the multipathd service active for this to work. We ran inconclusive tests by setting the "use_multipath_for_image_xfer" and "enforce_multipath_for_image_xfer" variables to true in cinder.conf. We also set the "volume_use_multipath variable" to true in the libvirt section of nova.conf, but without success.
After creating an instance and a volume on a server with Openstack, when querying the subsystem with the nvme command, we only get a single path. But when we query the backend from the same server with "nvme discover," we do get four paths.
In the os-brick code, we see that it checks a Multipath variable that must be set to true...
I think this is purely a configuration issue, but the examples given by various manufacturers (NetApp, PureStorage, etc.) don't indicate anything in particular.
So, does anyone know the configuration to apply for multipath to work (cinder/nova)?
Thank you.