Rabbit Launch: Loading up the NUC cluster with a usable operating system

As you saw in my 3D Printing series, after years of pondering a 3D printer, I was finally inspired to buy one when a pile of clusters came up on eBay from the defunct rabb.it video streaming service. In this series, I’ll take you through turning a rabbit door into some useful computing resources.

You can do something similar even after the clusters are sold out; a lot of people have probably bought the clusters and ended up not using them, so you’ll see boards on eBay or local marketplaces… or you can adjust the plans here to other models.

The previous installment, Rabbit Reorganization, can be found here. Stay tuned for more coverage.

Update December 2021: This post languished in the drafts folder for about a year. I’ve updated links, and I’ll be reporting on some changes since the October 2020 launch of this cluster soon.

Let’s NUC this cluster out

  1. Install memory, SATA cable, and SSD
  2. Upgrade BIOS and set some annoying settings
  3. Install your operating system
  4. Set up central control

Install memory, SATA cable, and SSD

This is the least interesting part of the process, but you’ll need to do it before you can install an OS.

Start by loading the SODIMM of your choice onto the board. If you’re using an SSD like I am, you’ll connect the SATA cable to the black SATA connector next to the front USB stack, and the power cable to the beige connector perpendicular to the SATA connector. If you’re using a standard SD card, plug it into the SD slot to the right (as shown with the MAC address label). If you’re going with netboot (local storage? where we’re going we don’t need local storage!), just connect your network cable.

Upgrade BIOS and set some annoying settings

I created a bootable FreeDOS USB drive with Rufus, a common free software product used to create bootable USB media from ISOs (think Linux, Windows, etc). From there, we get the latest BIOS from Intel’s Download Center and place the file on the bootable drive. (Further BIOS instructions available on Intel Support.)

As of December 2021, 0079 is the latest BIOS, released April 20, 2020. You’ll need to search for NUC5PPYH even though the board’s model is PPYB.

Connect a monitor and keyboard, plug in the bootable drive, and apply power (or just reset the board). Use the F7 key to go into onboard flash update and load the BIOS file from the flash drive, or choose to boot from the flash drive and use the DOS-style flasher from there.

When you’ve done the upgrade and the system has rebooted, go into the BIOS with the F2 key and choose BIOS default values. Then go into the menus to enable all the USB ports (for some reason the default is to enable ports 1-3, leaving physical port 4 and header ports 5-6 disabled) as well as the SATA port if you are using that for storage. I’d also check the boot order (move net boot down in preference or disable outright if you don’t plan to use it). You can choose other settings as desired, and then press F10 to save and reboot.

Install your operating system

The easiest way to roll out the NUC side of the door would be to netboot an installation infrastructure like Cobbler. One of the first things I did when I went to work for the Mouse 10 years ago was setting up Cobbler for a deployment of RHEL 5.5.

Sure enough, Cobbler is still a thing, with very recent updates. I was able to get partway there this time and then, after several dozen runs to the garage and back to power cycle nodes, I gave up and installed from local media.

For CentOS 8, I did a manual install booting from a Rufus-created USB drive, with the SSD installed. I configured my storage and network options by hand, as well as user and root credentials. This left an “anaconda.ks” kickstart file on the installed system, which I copied to a second flash drive.

For the additional systems, I plugged both the CentOS 8 installer and the drive with the kickstart file into the NUCs and booted from USB. I ran into some strange storage issues with the drive not being blank, despite having chosen the kickstart option. Ideally, you would boot from the USB installer, it would find your kickstart config, and just roll out the software without intervention from there.

After that, if your DHCP server doesn’t assign hostnames you like, you can go in and set hostnames with hostnamectl or the like.

Set up central control

If you use a configuration management platform like Ansible, Puppet, Chef, cfengine, or the like, you’ll want to set those up at this point.

I’ve gone with the lightweight method so far, with shared SSH keys from a management host (an Intel NUC with CentOS on it, originally intended to be the cobbler server).

Use ssh-keygen to create your key files, and then ssh-copy-id can be used to push out the keys to your hosts. Then look into a more manageable option.

Where do we go from here?

As I finish this post in December 2021, a year after the original build, I’m looking at going back and making a few changes to the cluster to bring it up as a Kubernetes platform.

With the demise of CentOS as many of us know it, I’m planning to replace the installed OSes with Ubuntu LTS. I’m planning to test out some cryptocurrency cpu-based mining, and run Kubernetes platform(s) on it as well, and bring my second door up to speed (the RAM has been sitting in a box in the living room for a year now).

There’s a chance I’ll even do some lightweight Chia farming, using either bus-powered USB hard drives or some of the extra power connectors from the fused expanders for standard Seagate externals.

For those of you who have bought and built up these doors, what did you do with them? Feel free to share details and blog post links in the comments. I’ll put interesting ones into the body of this post as I see them.

Increasing Chia farmer efficiency with Flexpool’s new ‘FlexFarmer’

There’s an updated Flexfarmer post aso f January 2022. Check out Revisiting Flexfarmer five months later.

You’ve probably seen my previous Chia posts, including how to build an efficient but sufficiently beefy plotter/farmer. As a long-time datacenter guy, I like building affordable, powerful servers.

Chia-specific cryptocurrency posts

However, as many farmers have found, if you plot and farm on the same machine, I/O can impact your farming performance, whether it’s disk I/O within the box, or writing off to a network share somewhere.

On top of that, you have to maintain a full Chia node, and optimally set up distributed harvesting with a somewhat complicated process. The full node currently requires about 13GB of local storage and frequent writes, so a Raspberry Pi or the like with an SD card is suboptimal. This also requires up to two days (for most computers) to sync the node initially, during which time you’re not at your best as a farmer.

Imagine if you could farm with the plots you have, using a tiny computer with very little CPU / RAM / storage requirements, without running and maintaining a full node, and saving 100W or more in the process.

Flexpool has just released their ‘FlexFarmer’ program which does just that.

Disclosure: I do work for Flexpool, but this post is based on my experience, not a press release or the pool admin’s expectations. Some of the testing I did was “on the clock” alongside support tasks, but I was not paid or required to write this post.

What does FlexFarmer do?

At a high level, FlexFarmer communicates with a node proxy on the pool server to communicate work and space, instead of requiring a local full node to operate. This means that anything that would require a full Chia node is handled on a powerful, resilient node at the Flexpool end.

You do still need to install the full Chia software to create your wallet. There will probably be ways around this in the future. You will also want a more formidable system for plotting, as the Raspberry Pi isn’t good for more than 1-2 plots a day.

Continue reading

Thirty Days On The Front Lines: A return to tech support

In September 1996, I left my desk at IQuest Internet in Indianapolis for the last time. A friend from the MUDs I was on had talked me into talking to her brother, a recruiter at Taos Mountain Software, and two weeks later I had an offer, notice given for my apartment and my job, and the terrifying thought of driving 2300 miles with my possessions in a Ryder truck, my very unhappy cat in the front of the truck, and my Pontiac Grand Prix on a trailer it was too heavy for.

But on the flip side, I was getting out of the Midwest and its glorious winters, escaping a salaried position that ended up being a pay cut, and most importantly, leaving behind end-user tech support. For the next 25 years or so, I did tech support, and infrastructure/architecture/caffeine delivery systems, but for internal colleagues who were generally more aligned with my assigned priorities.

Now, I’ve gone back onto the front lines, supporting end users from around the world in several different languages (thanks to Google Translate or Bing Translate), explaining and troubleshooting and answering questions about cryptocurrency in general, Ethereum and Chia in particular, and specifically how to make them work with one of the more advanced mining pools.

As I told the owner when I started, I’ll scale back or even hand over the reigns altogether when I find something more in line with Silicon Valley expense levels, but for now, it’s an extension of what I’d been doing on Telegram since January, and it’s supplementing my coffers in the process.

I meant to write this last month, when it would have been 30 days, but the conversations get overwhelming and blog posts get distracted-from, so here we are closer to 60 days in reality.

What’s it like working for a mining pool?

Continue reading

Frequently Ungoogled Chia Questions

This critter came in over the weekend. We’ll see if Hello Kitty grows chia faster than my rigs.

I’ve written a couple of Chia posts in the last week, and it looks like a lot of readers have benefitted from them.

There are still a lot of questions, many of them repeated, that people aren’t gleaning from the other posts. I’ll try to gather those here and update this page more often than the others. This will be somewhat freeform, so feel free to search this post or the blog in general for your answers, and if you have a new question, ask it here and I’ll see what I can do.

I will try to organize the questions and answers to make them easier to follow. For now, this is as-I-think-of-them so you may want to browse or use search to find your questions.

Note that I can’t do hardware audits, basic Linux or Windows admin training, or investment advice of any sort on this site. As with any crypto adventure, don’t spend more than you can afford to lose or repurpose, and don’t expect me to talk you into or out of any particular crypto efforts.

As a side note, no, the acronym was not intentional, but it’s relevant when I hear some of these questions. Thanks for asking.

Now on to the questions…

Updated: 2021-05-13 9pm PT

Continue reading

Building the Intel NUC Chia Plotter

In an earlier post, I shared a design for a Chia plotter/farmer based around the Intel NUC NUC10i7FNH tiny computer.

Today I built that machine, and it’s running its first plot as I type this.

If you landed here, you might be interested in my other recent Chia posts:

Pricing disclaimer: All prices, availability info, and links are accurate as of the writing of this article (May 3, 2021) unless otherwise noted. Prices vary from day to day and availability does too. Use this info with a grain of salt especially if you are reading this in 2022 or beyond.

Here’s a quick rundown of what was involved in the process.

Shopping List

Feel free to shop in your preferred venues online or locally, or if you already have components, use them. These links are Amazon affiliate links, and if you use them, I get a few bucks to go toward my next hardware adventure. (I bought my NUC and RAM from Central Computer, a local computer store in Silicon Valley, and the NVMe drive came from Amazon.)

Base computer – NUC10i7FNH1 currently $570 at Amazon. You want the i7, and you want the FNH which is the “high” case that holds a 2.5″ drive as well as the m.2.

RAM – 32GB (2x16GB) DDR4 2666 or better SODIMM. Crucial 16GBx2 kit around $182 at Amazon. You can install 64GB, but you probably don’t need it with this processor.

Boot drive – I used a Samsung PM851 that’s not available on Amazon at the moment. Any 2.5″ SATA drive will do, even a HDD. Amazon has the WD Blue SSD 250GB for $45 or 500GB for $60. If you have something else on hand that’s at least 120GB, go ahead and use it, or if you want some internal plot storage, get something bigger. 

Plotting drive – 2TB Inland Premium NVMe is popular with its 3200TBW rating, about $240 on Amazon but out of stock for the next week. If you watch your drive life, you can use cheaper NVMe or even SATA m.2 storage. But check the TBW (Total Bytes Written, or Terabytes Written) and warranty for your drive and take that into account. 

OS install drive – Get a USB 3.0 drive with 16GB or more space, and use Balena Etcher or Rufus to burn Ubuntu 20.04 LTS to it.I like the Sandisk Ultra 32GB for price point and quality, about $10 at Amazon

External long-term plot/farm storage – I’ll be using an 8TB external drive in the near term, but you can use whatever you have, even NAS storage. 

Bonus: Staging disk. A user on r/chia suggested using a staging drive to copy your final plot file to, so that your plot process ends faster than if it has to be copied to slow disk. You can then automate moving the plot files to your external HDD at your leisure, and get back to plotting again up to an hour faster. For this, you can use an external USB 3.0 or better SSD like the WD My Passport SSD ($150 for 1TB), Crucial X8 ($148 for 1TB), or pretty much any SSD that will hold a batch of your plots (1TB will hold 9 plot files). You can also use a directory on your NVMe drive for this, but make sure you don’t let it fill up.

Continue reading