Does AlphaVM run on a hyper-visor (like VMware, Hyper-V, ProxMox VE, etc).

Yes, AlphaVM is supported on several hyper-visors.

Supported Hyper-Visors.

  • VMware ESXi 5.5 and later
  • Hyper-V 2012R2 or later
  • ProxMox 4 and later.

VirtualBox

AlphaVM has also been reported to run on VirtualBox, but we do not support it. Older versions of VirtualBox incorrectly passes the host CPU capability flags. AlphaVM will not run with the flags passed by default. The flags can be corrected by the following command run from the Windows command prompt:

"C:\Program Files\Oracle\VirtualBox\VBoxManage" setextradata AlphaVM VBoxInternal/CPUM/CMPXCHG16B 1

Here AlphaVM is the name of the virtual appliance to be changed.

Performance Remarks

AlphaVM is a sort of a hyper-visor itself. When running on a hyper-visor one gets double virtualization, which has some consequences.

AlphaVM expects to use all the necessary resources provided by the hardware. In particular AlphaVM CPU expects to get a 100% of the host CPU. AlphaVM CPU is a single threaded workload with respect to the host CPU. Due to the hosting hyper-visor scheduling it can happen that AlphaVM does not get 100% of the host CPU, which will result in severe performance degradation.

It is similar with memory. If the hyper-visor swaps out AlphaVM memory, it causes severe performance degradation.

It is not recommended to run AlphaVM on a hyper-visor with over-committed resources.

AlphaVM SMP configurations suffer from the lack of resources even more than single CPU configurations. Each AlphaVM CPU runs in its own thread. Due to the hyper-visor scheduling these threads can get different host CPU resources, which can result in the CPU synchronization problems in the guest OS. In the worst case scenario on OpenVMS one can get an SMP timer watchdog errors: OpenVMS can think that a CPU hangs if it does not respond within a given timeout.

Conclusions

AlphaVM is supported on several hyper-visors. However, we do not recommend to run on hyper-visor if

  • The performance is important.
  • The realtime response is important.
  • It is SMP on over-committed hyper-visor.

We recommend that the hyper-visor VM hosting AlphaVM is configured with hardware resources fully available to it, in such a way that the preemption of AlphaVM is unlikely.

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