These are not cheap and nasty, or freebie USB drives, so I would not normally expect to see this rate of failures. The error only occurs when you reboot the host, and the startup bombs out at the start of the hypervisor launch. I have often managed to recover the stick by copying back corrupted files from another instance, but generally I needed to rebuild and restore the image. An unnecessary pain in the rear!
The Root Cause The NUC case can become quite warm during normal operation with or without the fans spinning up, and I have come to believe that the main reason for the corruptions is that the USB stick itself is getting too hot and therefore eventually failing. Having pulled a USB out from a recently shut down node, they are really quite hot to the touch. You don’t actually see the symptom / failure until a reboot because the ESXi image actually runs in memory, so is only loaded from the USB stick at boot time.
The Solution As for the solution, it’s really quite simple. I purchased a number of 12cm (5 inch) USB 2.0 extender cables on eBay for just 99p each (including delivery!).
These keep the USB stick indirectly attached to the NUC chassis, and as such the heat does not transfer into the flash drive. Since doing this I have not seen any further issues with the corruptions. Job done!
I successfully ran my VMware vSphere ESXi 5.1 Nanolab for 18 months on my pair of Intel NUC DC3217IYE hosts. Early this year I got around to upgrading to 5.5. I had experienced some issues with my vCenter Server Appliance so ended up just rebuilding the lab from scratch and reattaching my old data stores. Having written all of this up, I then promptly forgot to post it! So for the sake of continuity (before I do the same for 6.0 shortly), this article covers the process.
In addition I also purchased a 3rd node for my lab, the 4th Gen D34010WYKH model (also with a Core i3), with which I was able to test and prove the process on as it uses the same NIC chipset.
The following are updated instructions for installing vSphere 5.5 on Intel NUC (any model with the Intel® 82579V or Intel® I218V onboard NIC should work).
I recommend before you start, you upgrade the NUC to the latest firmware, to avoid any potential bugs (of which there were a few when they were first released). Copy the latest firmare image onto a USB stick, boot the NUC, hit F7 at the bios, find your firmware on the USB stick and let it do it’s thing:
Intel NUC Firmware Upgrade
vSphere 5.5 Install Requirements
A USB Stick. This should work on anything over 1-2GB but personally am using 8GB PNY Micro Sleek Attache & 16GB Kinston DataTraveler Micro drives as they’re tiny, so less likely to catch on anything as they stick out the back of the NUC box, and they cost less than £5 each.
A copy of VMware Workstation 8 / Fusion 6 or newer.
If you do choose to add this in as well to your image, simply run the customiser twice, once for the network VIB, then a second time for the SATA vin, using the interim image as your source for the final image.
Create a customised ISO with the additional Intel driver.
Install ESXi to your USB stick using VMware Workstation / VMware Fusion and the customised ISO you will create below.
Plug in your NUC, insert the USB stick, boot and go!
Part One – Create the Custom ISO
Run the ESXi-Customizer-v2.7.2.exe (latest version at time of writing).
This will extract the customer to the directory of your choosing.
Navigate to the new directory.
Run the ESXi-Customizer.cmd batch file. This will open up the GUI, where you can configure the following options:
Path to your ESXi Installer
Path to the Intel driver downloaded previously
Path where you want the new ISO to be saved
Ensure you tick the Create (U)EFI-bootable ISO checkbox.
ESXi-Customizer with 2.3.2 vib
This will output a new custom ESXi installer ISO called ESXi-5.x-Custom.iso or similar, in the path defined above.
Part Two – Install bootable ESXi to the USB stick.
I stress that this is my preferred way of doing this as an alternative is simply to burn your customised ISO to a CD/DVD and boot using a USB DVD-ROM. That would however be a whole lot slower, and waste a blank CD!
Plug your chosen USB stick into your PC.
Open VMware Workstation (8 or above), VMware Fusion, or whatever you use, ideally supporting the Virtualize Intel VT-x/EPT or AMD-V/RVI option (allowing you to nest 64-bit VMs).
Create a new VM, you can use any spec you like really, as ESXi always checks on boot, but I created one with the similar specs as my intended host, single socket, 2vCPU cores. RAM doesn’t really matter either but I use at least 4GB normally. This does not require a virtual hard disk.
Once the VM is created, and before you boot it, edit the CPU settings and tick the Virtualize Intel VT-x/EPT or AMD-V/RVI checkbox. This will reduce errors when installing ESXi (which checks to ensure it can virtualise 64-bit operating systems).
VMware Workstation Nesting
VMware Fusion Nesting
Set the CD/DVD (IDE) configuration to Use ISO image file, and point this to the customised ISO created earlier.
Once the above settings have been configured, power on the VM.
As soon as the VM is powered on, in the bottom right of the screen, right click on the flash disk icon, and click Connect (Disconnect from Host).
Attach USB in VMware Workstation
Attach USB in VMware Fusion
This will mount the USB stick inside the VM, and allow you to do a standard ESXi installation onto the stick.
At the end of the installation, disconnect the stick, un-mount and unplug it.
Part Three – Boot and go!
This is the easy bit, assuming you don’t have any of the HDMI issues I mentioned in the first post!
Plug your newly installed USB stick into the back of the NUC.
Don’t forget to plug in a network cable (duh!) and keyboard for the initial configuration. If you wish to modify any bios settings (optional), you will also ideally need a mouse as the NUC runs Visual BIOS.
Power on the NUC…
Any questions/comments, please feel free to hit me up on twitter as I have recently disabled comments on my blog due to the insane volumes of spam bots they were attracting!
If you are using your Intel NUCs with any anger, they will likely run reasonably hot to the touch and typically you would just place them horizontally on a surface as per the pictures above. For optimum performance and lifespan, we all know it’s always important to keep your NUCs as cool as possible!
The NUCs are also designed to be mounted vertically on the back of a monitor/stand/wall/desk or similar, using the VESA mount. What I didn’t realise is that whether mounted or not, if you run them on their side, they seem to actually maintain lower temperatures.
I’m not sure if the same would apply for the newer generation of NUCs with the 2.5″ drive cages, which also have small vents down the side, but it certainly works on the standard models.
Vertical running of NUCs
This seems to work pretty well for me, but as always, I take no responsibility if your NUC explodes with the fire of a thousand suns!
For those of you who are regular followers of my blog, you will know I am a great proponent of the Intel NUC range for their low noise, low power, low(ish) cost, high performance and most importantly high WAF (Wife Acceptance Factor) features!
Unbelievably having only just announced their second generation triumvirate of models just 2 months ago (and due out in a couple of weeks), they’re at it again, announcing a third generation already! The new models include a pair of Haswell-based “Wilson Canyon” Core i3 / Core i5 processor options, featuring up to 4 USB 3.0 ports and a full size SATA connector and are expected to land some time around Q3 this year.
I have updated the CPU table with the currently available info on the new models, and will add CPU benchmarks once available on www.cpubenchmark.net (for consistency). This also includes the recently leaked specs for the new Gen 8 HP Microservers based on Intel Pentium / Celeron processors.
Cores / Threads / Logical CPUs
Clock Speed / Turbo (GHz)
Max TDP (Watts)
Intel Celeron 847
1.1 / None
Intel Core i3-3217U
2 / 2 / 4
1.80 / None
Intel Core i5-3427U
2 / 2 / 4
1.80 / 2.80
vPro & VT-d
Intel Core i7-3537U
2 / 2 / 4
2.00 / 3.10
Intel Core i3-4010U
2 / 2 / 4
1.70 / None
Intel Core i5-4250U
2 / 2 / 4
1.30 / 2.6
AMD Athlon II Neo N36L
2 / 1 / 2
1.30 / None
AMD Turion II Neo N40L
2 / 2 / 4
1.50 / None
AMD Turion II Neo N54L
2 / 2 / 4
2.20 / None
Intel Celeron G530T
2 / 2 / 4
2.00 / None
Intel Pentium G630T
2 / 1 / 2
2.30 / None
IMHO you cant beat the NUC for its price / performance / noise features mentioned above. In an ideal world I would be happy to give up 2-3cm of extra board size to get some extra RAM slots and a second gig port on the VMware HCL in there, but as a tidy home lab solution they’re hard to beat!
As regards this latest batch of models, I personally still think the sweet spot is with the Intel Core i5-3427U DC53427HYE 2nd Gen model, which includes vPro for remote access, and will turbo to a handsome 2.8GHz for as little as ~£235 when I last checked. More than enough for most home lab requirements!