Monthly Archives: April 2015

Error 25325 when creating Hyper-V cluster on VMM 2012 R2

I’m currently studying for the 70-414 exam and following the course provided by I’ve been following the videos on setting up a Hyper-V cluster using System Center Virtual Machine Manager 2012 R2.

When I got to the step of creating the cluster it was failing in my demo lab. I kept getting this error:

Error (25325) The cluster creation failed because of the following error: Network has already been specified.

The network was dedicated to the iSCSI connections. I had configured two NICs on the same subnet, connected to a VM running Windows 2012 R2 iSCSI target with MPIO. It turns out VMM does not like having multiple adapters on the same subnet. Once one of the two adapters were disabled on both hosts, the cluster creation was successful. The adapters can be enabled again after cluster creation.


Building My Home Lab Part 3 – Installing ESXi

This will be a series of posts in which I describe how I have put together my Home Lab ESXi server.

Previous Parts:
Part 2 – Networking
Part 1 – Storage

Installing ESXi

Since the motherboard in my server supports Intel vPro, I can use the remote console feature to perform the installation and mount the VMware ESXi installer ISO remotely. The remote console feature requires RealVNC Plus, which will work in trial mode for 30 days, after which you need to purchase a licence.

vPro Setup

The first step in setting up vPro is configuring the network address. This is done from within the system bios. Further configuration can then be done from the browser by going to the URL http://<IP Address>:16992. You will need to enter the username (admin) and the password (set in the bios) to login.

Further vPro configuration can be done by downloading the Intel Open Manageability Toolkit at The Manageability Commander Tool can be used to configure remote control as well as initiate a remote control session. Be aware that only basic Serial over LAN is provided. Remote control still requires the use of an AMT compatible VNC client.

Connecting to the remote console

Power on the server. I found it is best NOT to power on the server from the console as this prevents the NICs from switching to gigabit speed. They remain on 10mbit to keep the console connection up.

Start RealVNC Plus. Enter the vPro interface IP address and select Intel AMT from the drop down list. You will most likely see the “no boot media” bios error. You can now mount the ESXi iso.

ESXi Installation

Installing ESXi is pretty straight forward. Just follow the prompts. The installer will automatically set up the destination disk and will reboot when it is complete.

Initial ESXi Configuration

You will be presented with a yellow and black screen with the ESXi version information. This is the Direct Console User Interface (DCUI). From here you can login as root (password is set during installation) and configure basic settings such as management network adapters. Select the adapter you want to use for the management interface. This will be the IP address used to connect the vSphere client to the host.

In Part 4 I will go over how I configured storage for the server, using a VM with a SAS HBA directly connected.