Ceph

While the roles stanza determines how many workers are needed to complete the test, it says nothing about the parameters of these workers. Workers can be bare-metal machines (which need a --machine-type definition), VPSs (VMs provisioned automatically by teuthology), or OpenStack instances. When using OpenStack, we can use the openstack stanza to specify minimum capabilities that the instance must satisfy.

"Tests can specify as many OSDs as they like and these are automatically provisioned and attached to the VM."

This is semi manual. If nothing is written, all happens in the root directory, even if the test needs 3 OSDs. If an OpenStack stanza is added to the test (see https://github.com/ceph/ceph-qa-suite/blob/master/suites/ceph-disk/basic/tasks/ceph-disk.yaml#L6 for an example and https://github.com/dachary/teuthology/tree/openstack#defining-instances-flavor-and-volumes for the full documentation), then extra OpenStack volumes are provisionned and attached to each VM created.