Lenovo ThinkCentre M75q Gen 2 ESXi 7.0 U3 install guide

 The last year or two hasn't been kind to homelabbers' budgets. Supply chain issues have had an insurmountable impact not only on new parts and servers, but on the second hand market as businesses desperately snap up what they need. Fortunately, supply chain and global economic recovery are making both availability and pricing of some components affordable again.

In a previous blog post, I touched on the options available for servers. Mini PCs and NUC like systems offer a lot of value, especially with the Fling drivers that add Intel and Realtek USB NIC functionality. The Fling drivers allow for USB network cards to be added to systems that have limited or no supported network adapters. Such is the case with the Lenovo ThinkCentre M75q Gen 2. It only has one network card onboard, the RealTek 8111 gigabit adapter. RealTek does not make a driver for ESXi, and while drivers have existed in the past, they were vmklinux and community based, meaning they do not work in ESXi 7.0. There are also a handful of new Intel network cards that do not have a supported driver, but this is answered by a Fling driver as well. The workaround is to add gigabit and 2.5GbE USB network cards to the system, and inject the Fling driver to the ESXi image prior to install. 

Hardware wise, I have added a CableCreation USB 3.0 Gigabit LAN 2.5Gbe adapter for the storage network, as well as a TP-Link UE300 Gigabit adapter for management.

To do so, we will need to install PowerCLI. I'll include the install commands which were taken from this link:

1. Open PowerShell as an administrator
2. Run the following command: Install-Module VMware.PowerCLI -Scope CurrentUser
3. Press "y" if prompted, then enter

The next steps are borrowed directly from the first objective of the VCAP exam. 

1. Add an offline bundle to work with, in this case I'm using an offline bundle I created previously:
• Add-EsxSoftwareDepot ESXi-7.0U3-USBNIC.zip
2. List the profile(s) available within that offline bundle, and make note of it:
• Get-EsxImageProfile (in this case, it listed ESXi-7.0U3-USBNIC as the profile)
3. Add the fling driver:
• Add-EsxSoftwareDepot ESXi703-VMKUSB-NIC-FLING-51233328-component-18902399.zip (this will change in the future, be sure the filename matches!)
4. Clone the profile:
• New-EsxImageProfile -CloneProfile "ESXi-7.0U3-USBNIC" -name "ESXi-7.0U3-injected" -Vendor "vshoestring"
5. Add the Fling software package to the newly created profile:
• Add-EsxSoftwarePackage -ImageProfile "ESXi-7.0U3-injected" -SoftwarePackage "vmkusb-nic-fling"
6. Export to ISO:
• Export-ESXImageProfile -ImageProfile "ESXi-7.0U3-injected" -ExportToIso -filepath ESXi-7.0U3-injected.iso

Note that if you have issues exporting to ISO, you might have to export it to an offline bundle first then repeat the process above with the new offline bundle. To export it to an offline bundle instead:

• Export-ESXImageProfile -ImageProfile "ESXi-7.0U3-injected" -ExportToBundle -filepath ESXi-7.0U3-injected.zip

One caveat that I've run into with using a system that only utilizes RealTek USB NICs is that the install process will halt as the system does not detect supported network cards. If you reboot, it will boot to ESXi just fine but will not store the configured password - use a blank password to configure the host.

Another issue is that on reboot, vmnic configuration isn't maintained on the virtual switches. This is due to the USB driver loading out of order. The only fix I've found is to manually reconfigure the management network adapter. Once complete, remove other vmnics from the virtual switches then re-add them.

The benefits of the M75q Gen 2 is that the CPU performance is on par with some of the Intel Xeon processors that I have in my lab currently. Granted, they are 6-8 years old at this point, but at a fraction of the power consumption, it is something that I can feel comfortable keeping powered on 24/7 without much consequence. My next blog post will compare power consumption benchmarking.