XCP-ng
Update a host:
login using putty
yum check-update
yum update
y
shutdown -r
xe vm-list
uuid ( RO) : 24afcbdd-b145-4d5e-b4b3-949f57c59b96
name-label ( RW): Control domain on host: xcp-ng-1
power-state ( RO): running
uuid ( RO) : 7adc9f19-90b2-e3db-f5c4-454eae8b888a
name-label ( RW): XOA
power-state ( RO): halted
xe vm-start uuid=7adc9f19-90b2-e3db-f5c4-454eae8b888a