Information Technology Reference
In-Depth Information
Examining Virtual Machines from the Outside
To better understand what a VM is, you must consider more than just how a VM appears from
the perspective of the guest OS instance (for example, from the “inside”), as we've just done. You
must also consider how a VM appears from the “outside.” In other words, you must consider
how the VM appears to the ESXi host running the VM.
From the perspective of an ESXi host, a VM consists of several types of i les stored on a sup-
ported storage device. The two most common i les that compose a VM are the coni guration i le
and the virtual hard disk i le. The coni guration i le—hereafter referred to as the VMX i le—is
a plain-text i le identii ed by a .vmx i lename extension, and it functions as the structural dei ni-
tion of the VM. The VMX i le dei nes the virtual hardware that resides in the VM. The num-
ber of processors, the amount of RAM, the number of network adapters, the associated MAC
addresses, the networks to which the network adapters connect, and the number, names, and
locations of all virtual hard drives are stored in the coni guration i le.
Listing 9.1 shows a sample VMX i le for a VM named win2k12-01.
Listing 9.1:
Example virtual machine confi guration (VMX) fi le
.encoding = “UTF-8”
config.version = “8”
virtualHW.version = “10”
nvram = “Win2k12-01.nvram”
pciBridge0.present = “TRUE”
svga.present = “TRUE”
pciBridge4.present = “TRUE”
pciBridge4.virtualDev = “pcieRootPort”
pciBridge4.functions = “8”
pciBridge5.present = “TRUE”
pciBridge5.virtualDev = “pcieRootPort”
pciBridge5.functions = “8”
pciBridge6.present = “TRUE”
pciBridge6.virtualDev = “pcieRootPort”
pciBridge6.functions = “8”
pciBridge7.present = “TRUE”
pciBridge7.virtualDev = “pcieRootPort”
pciBridge7.functions = “8”
vmci0.present = “TRUE”
hpet0.present = “TRUE”
displayName = “Win2k12-01”
extendedConfigFile = “Win2k12-01.vmxf”
virtualHW.productCompatibility = “hosted”
scsi0.present = “TRUE”
disk.EnableUUID = “TRUE”
ide1:0.present = “TRUE”
ethernet0.present = “TRUE”
guestOS = “windows8srv-64”
memSize = “3072”
