A vSphere administrator manages a three host cluster with 20 VMs. The HA cluster is configured with the Host Failures the Cluster Tolerates admission control policy and all other settings are set to d

Lowering das.vmcpumaxmhz reduces the maximum per-VM CPU value factored into slot sizing, which would shrink available capacity and make it harder - not easier - for the large-reservation VM to power on.

Raising das.vmcpuminmhz sets a higher minimum per-VM CPU slot floor, which increases each slot's size and reduces the total number of available slots across the cluster, worsening the admission control problem.

das.slotcpuoutmhz is not a recognized standard vSphere HA advanced attribute, so modifying it would have no effect on slot-based admission control.

The das.slotcpuinmhz advanced attribute manually overrides the CPU component of the HA slot size, which by default is derived from the largest CPU reservation in the cluster. If a VM's CPU reservation is very large relative to the defined slot size or the automatically computed slot is inflating the total slot count such that admission is denied, increasing das.slotcpuinmhz to explicitly define a slot large enough to accommodate the VM allows HA admission control to grant the power-on request.