When you load the parallel port driver modules in the service console, the following warning messages might appear in the VMkernel boot logs:
WARNING: Host: XVMKSyscall_HostEnableInterrupt:2646: irq not set up 47
The warnings appear in the VMkernel boot log as a set, in which the last number in the message changes and runs in ascending or descending order.
These messages are caused by loading the parallel port driver in the service console. They are warning messages that can be ignored. The ESX Server 3.5.x host still boots successfully.
Based on VMware KB 1003091