I was wondering weather someone else has experienced this issue.
It seems like 3.14 with XEN does not work on certain x86 hardware.
The boot stops at a certain point bugging you about the console. The same installation on different hardware works fine… well it boots i did not get the chance to do any more testing.
Any suggestions? 
P.S. reverted to 3.13 which does the job for me… 
there have been a lot of patches in 3.15, wait for that version and lets see, what have improved and what slipped by
janisk: when 3.15 will be released?
It is planned to release 3.15 very very soon.
3.14 and 3.15 both drive my older super micro board batty !!
I am re-installing via net install with out zen.. As this is an oder CPU I want to see if it is the hypervisor causing the issue..
There is still an issue on this one… I set out this morning to track down what the problem is. I know it’s been a long time since my last post but i thought i’ll give it a go now that we have the stable version 3.17.
The same problem again and a kernel panic gave me a warm welcome.
Figured out that something is not right when I have wireless cards on the router + XEN with version greater than 3.13. Taking out the wireless cards or downgrading to 3.13 makes everything work fine (leaving out the wireless settings loss after the downgrade… always be prepared with a last good working backup). I managed to replicate the problem on another system with the same drive so that i could take some screenshots and swap in out wifi cards (the original system is on a roof).
Similar problems have been reported by other colleagues that have taken the XEN plunge on a powerful wifi x86 router.
Supout and screenshots are on the way.
To be on the safe side… >3.13+XEN+Wireless… don’t try this at home… 
or on important router. confirmed and working on a fix.
I have v3.13 installed currently handling 7 WiFi connections. All of my cards are Winstron CM9 and the RouterOS is running on a P4 3GHz with 512 RAM from a hard disk. I also run a guest RouterOS via XEN to just handle all of my VPN connections.
Yesterday I’ve tried to upgrade the system to v 3.17… but… It simply doesn’t want to upgrade with 3.17 + XEN + WiFi.
At the end I’ve done a clean install including the XEN package (with a 3.17 CD made from the iso file) without the WiFi cards and all worked well. It booted fine but as soon as I installed on the system at least 1 WiFi card then it all went wrong.
I’ve even tried the disk on 2 other systems (all Intel x86 based) but there is no way to get XEN with wifi together.
The OS doesn’t even boot, it crashes on startup with quite a few errors showing on the screen. You just remove the WiFi cards and all is fine.
Any news regarding a fix? Isn’t v 3.17 supposed to be stable?
PS. I’m now at v 3.13 and all is back to normal.
v3.17 is stable version.
Xen package is highly experimental.
An older Tyan board (has worked with all versions since 2.8X)..
When Xen loads, loads, there is a debug output RE Intel driver then OS continues to load, but no wireless interfaces..
To remove XEN package. remove ALL wirelsss and sync interfaces, (hardware) and then the XEN package will uninstall..
(When XEN is active) system will not even reboot.. it hangs on system reboot / shutdown.
My guess is that the older chipset and more importantly the CPU has an issue with XEN..
it is not much chip-set as it is CPU supported features.
You mean that the CPU has to have VT..?
Thats my guess.
Can someone from MikroTik confirm that the XEN needs to have a VT compatible CPU to function?
The funny this is that on 3.13 it works fine without a VT enabled CPU.
VT is needed if you want to run Win2k8. Without VT you can run only machines that have compiled kernels as domU.
ayufan
Has anyone tried the new 3.18 if it’s ok with WiFi nad XEN ?
@ janisk CPU support issue? Explain please…
To the others… only paravirt machines run on MT. Actually you do not need VT or AMD-V at all. I do not want to imagine a windows server machine on a ΜΤ router.
Install a new Linux distro on a proper machine if you want XEN, install Citrix XenServer or grab an ESXi or ESX lic… Get a grip XEN on MT in my own eyes is only intended for V-routers, V-bridges, V-MT in general and the like. On a bit more complex scenario maybe a paravirt linux installation that only does basic stuff (dns, a small sip server and the like). Xen on MT opens new doors but don’t get too carried away.
By the way, news on this issue would be very much appreciated… Thanks
on very old CPUs xen is not working. VT and AMD-V is not needed for XEN in RouterOS to function.
so, if you have problems running XEN, then include cpu version, not jusy only motherboard mode.
and as written before - you have to have XEN enabled kernel to run it under RouterOS.
2,4GHz P4 by the way. Its a 6 iface wifi router with another Virtual MT to do some other network routing stuff..
CPU is not a prob since a similar machine with no wifi works OK.
All P4s should work ok with all Xen Versions for paravirt machines
Thanks for the answer 
3.18 with xen is not working for you if there is wireless interface?
P4 should run RouterOS with XEN