In the VM can be installed as applications that consume little system resources, as well as loaded applications. Applications with cyclic loading can also be installed. For example, when reporting, the load increases, the virtual machine needs to add resources (vCPU, memory, disks can be transferred to a faster storage). When the load decreases, the resources are reduced. There may be clustered applications Microsoft SQL Always-on Availability Groups (AAG), Microsoft Exchange Database Availability Groups (DAG) and Oracle Real Application Clusters (RAC), Windows Server Failover Clusters (WSFC).
It makes no sense to run a VM that constantly consumes a lot of resources, especially if the size goes beyond NUMA.
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