Citrix have announced that as of XenServer 7.3, the free version (including the ‘opensource’ version packaged by Citrix) will no longer have feature parity with the paid-for Standard version. Of the features which are restricted in the free version, a maximum pool size of 3 hosts and the removal of Xen Storage Motion are going to make the use of free XenServer to run production clouds pretty much untenable.