What is VMware Misc.SIOControlFlag2? Misc.SIOControlFlag2 is used by VMware ESXi hosts to keep track of Storage IO Control (SIOC) usage.
If you’re not using SIOC, then the setting doesn’t have any impact on your environment. If you are using SIOC, then Misc.SIOControlFlag2 is used by the vCenter to know about the activity on volumes from hosts (specifically, it tells the SIOC Injector when to charactorize the volume).
In either case, you shouldn’t change the value of Misc.SIOControlFlag2, because it’s internal to the operation of VMware vSphere.