It may happen that the Exchange Health Checker displays the following error in the report:
Dynamic Memory Detected: True 0GB is the allowed dynamic memory of the server. Not supported to have dynamic memory configured.
Dieser Fehler wird bei virtualisierten Exchange Servern angezeigt, bei denen das Feature „Dynamic Memory“ für die VM aktiviert ist. Dynamic Memory wird für Exchange Server nicht unterstützt, daher zeigt der Exchange Health Checker diesen Fehler. Dieser Fehler kann bei Exchange Sevrern auftreten, welche mittels VMware oder HyperV virtualisiert wurden.
Um den Fehler zu beheben, muss bei einer VMware basierten VM der komplette Arbeitsspeicher der VM reserviert werden. Die entsprechende Einstellung findet sich in den Eigenschaften der VM unter dem Punkt Memory und heißt „Reserve all guest memory (All locked)“:
„Reserve all guest memory“ muss aktiviert werden, damit Dynamic Memory abgeschaltet wird.
With a Hyper-V based VM, Dynamic Memory can also be switched off in the properties of the VM:
If Dynamic Memory was activated on the VMs, the hypervisor can no longer use unused RAM of the VM for other VMs. The entire working memory of the virtual machine must therefore be reserved and also be available on the hypervisor. Microsoft writes in addition:
Some hypervisors can overbook or dynamically adjust the available memory for a particular guest machine based on the perceived memory usage in the guest machine compared to the requirements of other guest machines managed by the same hypervisor. This technology is useful for workloads where memory is only needed for a short period of time and can then be freed up for other purposes. However, it is unsuitable for workloads that require continuous memory. Exchange (like many server applications that use in-memory data caching to optimize performance) is prone to poor system performance and an unacceptable user experience if it does not have full control over the memory allocated to the physical or virtual machine on which it is running. Therefore, the use of dynamic memory or memory overcommitment features is not supported for Exchange.