hvmloader seems to be broken

I have narrowed down a server reboot issue to the new xen 4.0 in debian squeeze.

If you try to boot with the kernel = "/usr/lib/xen-default/boot/hvmloader" it crashes the entire server.

See the attached logs.



Ok .. but since Cloudmin is built on top of open-source Xen tools, there isn't much we can do about this :-(

Unless there is some alternative to hvmloader?

Frankly with all the issues and the manual grub2 changes that have to be done just to get xen working I think you shouldn't support debian anymore, at the least nothing newer then lenny.

Personally I've found they run OK on a CentOS 5 host system ..

CentOS is not debian -- not even close so you can't even compare the two.

I am telling you that the testing I did on 2 servers yelded the same results. With debian squeeze Xen support is going to be way to complex to support.

Just getting grub2 to boot the proper xen kernel is going to require a manual boot change that CM is not going to be able to do.

Just read https://www.virtualmin.com/node/17675 if you haven't.

I have already suggested to my clients to switch to xen server instead of xen source because of this. Both agreed after what I showed them.

Sure, CentOS is different .. but I don't see the problem with using it on your host systems to run Debian VMs. In my experience it has been much more reliable.

I still don't see what the hell CentOS has to do with this ? The bug is filed against Debian Squeeze. If you arent going to test with a Squeeze Dom0 then don't bother.... But still say that xen support in debian squeeze is spotty and needs more to make it user friendly and work with HVM boots.

I think i found a solution for this problem... Or at least the cause ...

We have many machines with HVM Xen domUs... I was wondering, what is the difference between manually created VMs and cloudmin VMs... If you use maxmem in your Xen Config (cloudmin do so by default) your VM will crash the entire system...

Bug if you select limit "Maximum memory for Xen instances: Limit set at boot time MB" in your Open Source Xen settings, cloudmin will not add the "maxmem" parameter to your config and you can start HVM DomUs successfully... :)