Trying something new... Remove all servers from XO and log out. Host 1 is powered off. On host 2. xe task-list uuid ( RO) : 727ecb6b-6f2e-15eb-601b-110b2478996b name-label ( RO): Async.host.power_on name-description ( RO): status ( RO): pending progress ( RO): 0.000 xe task-cancel uuid=727ecb6b-6f2e-15eb-601b-110b2478996b Task is still there. From XCP-NG Center. Shutdown all VMs and host2 (All powered off). Powered up both servers. Wait 15 minutes to make sure no tasks are pending (xe task-list). Logging output to file via putty of; tail -f /var/log/audit.log Added host2 (master) to XO Settings/Servers. The Async.host.power_on task hasn't come back.