Virtual Machine CPU / Memory scaling with Hot Add

The main drawback of enabling Hot Add is a potential performance drop, as VMware recommends activating it only for resources where this functionality will be actively utilized. According to VMware, this can lead to a performance drop of up to 10%, but the extent of the impact largely depends on the application. Particularly, SQL VMs and other applications capable of leveraging NUMA CPU topology would be most affected. It's worth noting that Hot Add support depends on the operating system; while newer OS typically supports it, older ones may encounter issues, such as Kernel Panic. Additionally, Hot Add does not support Hot Remove, meaning that to reduce resources, VMs will still need to be turned off.