Documentation #17978
closedWrong diskcache parameter name for OpenStack Havana and Icehouse
0%
Description
I've been investigating some performance issues I've encountered on an OpenStack Icehouse deployment. The configuration closely resembles the one from http://docs.ceph.com/docs/master/rbd/rbd-openstack/.
However, libvirt was using "none" as disk cache mode despite the configuration line in nova.conf:
libvirt_disk_cachemodes="network=writeback"
A closer examination revealed that the correct configuration would have been:
disk_cachemodes="network=writeback"
Due to an unknown reason there is no deprecated_name with a libvirt prefix for the disk_cachemodes configuration option (see https://github.com/angdraug/nova/blob/rbd-ephemeral-clone-stable-icehouse/nova/virt/libvirt/driver.py#L252). This holds for both OpenStack Havana and Icehouse. It is possible at least for Icehouse to use the configuration for Juno, which (implicitly) fixes the wrong parameter name.
Updated by Nathan Cutler about 7 years ago
@michael rodriguez: Can you open a PR at https://github.com/ceph/ceph with your proposed fix? The documentation is under doc/
Updated by Jason Dillaman about 7 years ago
@michael rodriguez: note that Icehouse and Havana are both EOLed by the upstream community. Does this issue apply to Grizzly+ releases of OpenStack as well?
Updated by Michael Eischer about 7 years ago
I've opened a pull request: https://github.com/ceph/ceph/pull/13403
@Jason Borden: The documentation fix doesn't apply to OpenStack Juno or later which have their own documentation section(s). OpenStack Grizzly is not covered by the rbd documentation, but also doesn't seem to have the 'libvirt_' prefix for disk_cachemodes.