Virtual Machine restarts when CPU utilization goes 100 percent

[AdityaM]

Hello,
I have observed one strange behavior with VMs on Windows host, that when the CPU utilization reaches towards 100 percent then the OS running in my Virtual Machine restarts itself. Although the VM itself is always in 'Running' state, it never changes state to 'Starting' or 'Powered-off' in this case.
Is it the expected behavior? Can I avoid it?
I am running VxWorks RTOS on my virtual machine and I am using Version 5.1.22 of Oracle Virtual Box, on Windows 7 host.
So it could be the issue of virtual machine or the OS running inside the virtual machine?
Please suggest some help on this topic.
Let me know in case any other information is required from my side.
Thanks
Aditya Mittal

[scottgus1]

I google that VxWorks RTOS is a "real-time operating system". I would suppose that if virtual machines are anything they're probably not "real-time". Guests reaching full throttle on the CPU typically don't reset, but maybe this special OS is not compatible with virtualizing? See the manual, section 3.1, on the supported guest types - these listed OS's are supposed to work.

[mpack]

Being an RTOS it would be common practice to have a watchdog function which must be patted at a certain frequency to avoid a reset. The log should tell you who requested the reset.

[AdityaM]

Hello,
'scottgus1' and 'mpack', thanks for your replies. I checked in the manual in the suggested section 3.1, and VxWorks RTOS is not listed. So I guess there could be compatibility issues in the first place also. And one important point about watchdog timer is also mentioned in one of the replies, which even I am suspecting to be the culprit as one of the sources that could be causing a restart. I thought of that, and I am already trying to find out if watchdog is somehow causing this restart.
Meanwhile I posted this query to know and understand if anyone has previously encountered this kind of behavior with virtual machines.
Thanks any ways for starting pointers.
Regards
Aditya