4.3. SPM Priority
The SPM role uses some of a host's available resources. The SPM priority setting of a host alters the likelihood of the host being assigned the SPM role: a host with high SPM priority will be assigned the SPM role before a host with low SPM priority. Critical virtual machines on hosts with low SPM priority will not have to contend with SPM operations for host resources.
You can change a host's SPM priority in the SPM tab in the Edit Host window.