[kion]

To answer the 2nd part of the question:

vmnix was the name of the Linux kernel module that was loaded during the Service Console's boot process.

The terms "Service Console", "Console OS (COS)" were at times used interchangeably and referred to the Redhat distro you logged into at the terminal.

VSphere 4.0 had 2 versions: ESX (with COS) and ESXi (without COS). In 5.0 the COS was removed entirely.