UEFI is just a hell lot more complex than legacy BIOS is. This does not make it slower per se but on top of that a lot of the UEFI implementations are badly flawed. Feel free to take a tour through the iPXE code and see all the things that need to be done to properly boot UEFI machines…

@Junkhacker I had multiple hard drives I was trying to image at once and once this issue started popping up I actually did switch to re sizable but it was still having that issue strangely.

@Killklli Are you still working on this? I have done a lot of testing and I am pretty sure that dnsmasq is not able to boot most UEFI devices as it uses DHCP option 43 which they don’t like (see here: https://www.mail-archive.com/dnsmasq-discuss@lists.thekelleys.org.uk/msg09233.html). I am working on a node.js proxy DHCP to support BIOS/UEFI and Mac OS X. But will be still a while I suppose - BIOS works pretty good and UEFI is not far either but the code is still a big mess.

Follow this thread: https://forums.fogproject.org/topic/5870/dhcp-proxy-for-fog