The ABAP work processes on SAP NetWeaver 7.1 onward have an embedded "Virtual Machine Container". These are tiny java engines useful for Business Suite products like CRM, SRM and ERP. As PI systems are also built on NetWeaver, VMC is available on the ABAP stack of the PI system. PI does not require VMC and hence VMCs can be disabled to save memory and CPU resources.
To turn VMC off, set the following parameter in ABAP Instance or Default Profile:
vmcj/enable = off