If you talking about an ESXi Golden Image then you have to take the following steps:
1.) Download a pre-created OEM specific version of ESXi 5.5. For instance HP, Cisco and other vendors have this. This is a packaged version of ESXi with all of the vendors drivers for all of their products. This makes it so you don't have to setup additional drivers or vibs to get some peripherals working. If your vendor does not have a pre-packaged version of ESXi then you have to download the vanilla version of ESXi and import all the VIB's yourself with vSphere PowerCLI and re-package it back into an ISO.
It appears IBM alread does this for you so you can download the version you want: IBM System x and BladeCenter with VMware
2.) Once you have your ESXi image ready another thing you can do to create a ESXi "Golden Image" for consistency purpose is Host Profiles. You would put one of your current hosts in maintenance mode and create a host profile from it. You would then edit the answer file for the new machine and assign this host profile to it as soon as it comes online and has been brought into vCenter. This will put all the same settings as your previous host except IP address. This allows you to quickly provision new hosts.
Here is some further information on how to create / use Host Profiles: https://pubs.vmware.com/vsphere-55/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-55-host-profiles-guide.pdf
vCenter demo create ESXi host profile - YouTube
Now if your talking about a Windows Golden Image this process is a bit easier.
- You will create a new Windows Server and update it to the latest patch levels
- You will install any other software you will need on the server IE.) Anti-Virus, Line of business apps, IIS, Etc
You will then turn this image into a Vmware Template. However keep in mind every-time you deploy this template you will need to run the Configuration Wizard and make sure a new sid is generated which will sysprep the system.
If you have any other questions please let us know
I hope this has helped.
