I recently bought an Intel NUC 6th generation (Skylake-based Core i3) as a VMware ESXi host. This is an addition to my existing host that I assembled back in 2012. It has served me well over the years and hope that it will continue to do so for several more years. Four years old in the computing world is obsolete, but I think it is still a very capable machine for what I use it for. Having said that, it will still be running as another ESXi host.
You might be asking why in the world would someone need two ESXi hosts at home that is not even studying for VMware certifications. I do, however, want to point out that I wanted to take the VCP certification back then that was why I attended VMware vSphere Install, Configure, and Manage [V5] class in a community college back in 2012 – check my tweet about it. Anyway, the primary reason is that the 32GB RAM on my first ESXi host is beginning to be too limiting for my CCIE lab purposes. I have to manage the amount of VMs that are turned on or I will be doing a memory overcommit.
The secondary reason, which is related to the first one, is that I really want to run vCenter Server so I could play with vSphere Flash Read Cache and other stuff. The Flash Read Cache feature was mentioned to me by @matthaedo on his response to my tweet. I did a quick search about this feature since I did not know what it was, how to do it, etc. and found out that one of the requirements to take advantage of the Flash Read Cache feature is vCenter Server, which I did not have. Yes, I could’ve installed the trial version of vCenter then test it out in my existing host and be done with it. But, I really wanted to add another host anyway so that it can handle my other VMs and add vCenter Server Appliance. Fortunately, I found out that we have VMAP (VMware Academic Program) campus subscription. One of the things that this subscription gives us is that it allows any student, staff, or faculty to use VMware infrastructure products for personal use to gain hands-on experience. The program is similar to the VMUG Advantage but only few products are included. For example, we do not have access to VMware Virtual SAN in the portal but the VMUG Advantage’s EVALExperience does. So, if one is looking for VMware licenses that are relatively inexpensive ($200) then the VMUG Advantage subscription is the way to go. I just wish it includes .VMware NSX though
Let’s go shopping

At the time of writing, the Intel NUC 6th generation has four models shipping, two of them have identical Core i3 CPU and the other two have identical Core i5 CPU. The four models are NUC6i3SYK, NUC6i3SYH, NUC6i5SYK, and NUC6i5SYH. The main differences between identical CPU models are the size of the enclosure and the SATA3. Models with SYH at the end have the space for 2.5″ HDD or SSD and of course the SATA3 connector for it. The NUC6i7KYK – Skull Canyon is now available for purchase and ESXi 6.0 U2 can be installed with BIOS changes.
There have been several virtualization folks who had been running Intel NUC for years. The earlier NUCs are not compatible with the official ESXi ISO so it requires a customized ISO that contains proper drivers to install ESXi. With the 6th generation, it is no longer needed to create a custom ISO making it a seamless install.
Without further delay, here are the parts of my ESXi host:
1 x Intel NUC6i3SYH
1 x G.SKILL 32GB (2 x 16GB) F4-2133C15D-32GRS
1 x Sandisk Cruzer Blade 8GB USB Flash Drive (not pictured)
1 x OCZ Deneva 2 C Series 240GB D2CSTK251A20-0240 (not pictured)
I just happened to have the USB flash drive and OCZ SSD drive so feel free to buy the alternative parts listed below:
1 x Crucial 32GB (2 x 16GB) CT2K16G4SFD8213
1 x Sandisk Cruzer Fit 8GB
1 x Samsung 850 EVO 250GB 2.5″ SSD and/or 1 x Samsung 850 250GB EVO M.2
If you decide that you want additional NIC, then you may want to purchase the StarTech USB 3.0 NIC. Right out of the box, it won’t work but with a little tweaking then you could definitely make it work.
At this time of writing, the Crucial ($165) is cheaper than the G.SKILL ($180) so buy the Crucial instead. I just happened to get the G.SKILL a little bit cheaper than Crucial when I bought the parts. If you do not need the SSD since you have a NAS (I have the Synology DS1812+) then forget about the links above. In fact, my other ESXi host does not have an HDD or SSD installed in it. Though, that may change in the future. I already have Samsung 850 EVO 1TB SSD in my NAS to speed the VMs up but I might still buy one for Flash Read Cache.
Installation
Before installing ESXi 6.0 Update 2 on the Intel NUC, I suggest checking the BIOS version first. Mine came with BIOS version 24, which was released in Oct 2015. The new version is 36, which was released last month, can be downloaded directly from Intel’s download page. The BIOS will work on all four models so be sure to download and apply it first before doing something else. Upgrading the BIOS was very easy. All I did was download the SY0036.BIO file, copied it to a USB flash drive, and powered on the NUC with the USB flash drive in it and hit the F7 key. Then, the NUC recognized that there was a BIO file then I followed the screen prompts to install the new BIOS.
After the BIOS was complete, I head back to my other computer and tried to create ESXi 6.0U2 ISO using UNetbootin. I’ve used that in the past and have successfully installed the different OS using the bootable USB created from UNetbootin. However, this time around, UNetbootin did not recognize my USB flash drive for some reason. My Windows recognized that there was a USB flash drive but UNetbootin did not. I then decided to use Rufus and created the ESXi bootable USB flash drive and it recognized the USB flash drive just fine.
Next, I booted the NUC with the USB flash drive and entered BIOS settings to make sure that the boot order was correct so that every time that the NUC reboots, it always tries to boot from the USB. Once ESXi installer files were loaded to the RAM, I followed the screen prompts and picked the same USB flash drive I used to boot it from as the destination drive for the ESXi files.

Thoughts
As you can tell from my tweet, I’ve only had the Intel NUC for two days but I am quite pleased with it. I am not going to lie but I wish my NUC had more oomph. I could’ve gotten the Core i5 or wait for the Core i7, which in theory, should provide more oomph but stay under $500 was important. The $90 difference in Core i5 is probably not much but I’ve spent quite a bit of tech stuff for that past few months, like my router, managed switches, and 1TB SSD. If I ever need more compute power, I could use the vMotion feature to move it to my Xeon-based ESXi host and run it from there.
I also noticed that the NIC doesn’t seem to work correctly when I set it to 9K MTU. I kept getting an error message and when I did a quick search one guy said that it means that the NIC does not support the jumbo frame. However, one reader said that the NIC itself supports the jumbo frame but the driver might be the culprit. It’s not really a big deal but it would’ve been great if I could’ve used 9K MTU without doing some tweaking. The majority of my wired devices are already set to 9K so this is another odd man out.
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