If you delete a QoS policy that is in use or disable a system class that is used in a QoS policy, any vNIC which uses that QoS policy is assigned to the Best Effort Priority system class. In a system that implements multi-tenancy, Cisco UCS Manager first attempts to find a matching QoS policy in the organization hierarchy.
The following deletes the QoS policy named QosPolicy34 and commits the transaction:
UCS-A# scope org /
UCS-A /org # delete qos-policy QosPolicy34
UCS-A /org* # commit-buffer
UCS-A /org #