Migrating Home Assistant to an Intel NUC

Yes, I know I’ve been pretty relentless about Home Assistant when I’m supposed to be a die-hard HomeKit fan. And that’s completely true, out of all the home-automation ecosystems I’ve tried, HomeKit is by far my favorite. It works really well, it’s easy to set up, and the automations aren’t too complicated… but it’s missing a few things and, in my case, I could never fully get rid of the delay between Aqara wall switches and Philips Hue lights. With Home Assistant, that delay disappeared from minute one. Home Assistant isn’t perfect. You’ll remember what I told you a few weeks ago when I talked about all the limitations I’d run into with Home Assistant, some due to my lack of knowledge and others due to the project’s lack of maturity — because even though it’s a super active project with a great community behind it, there are still things that need polishing or implementing. One of these limitations is exactly what I want to talk to you about today: high availability and fault tolerance. Some of the folks from the Domótica Compatible Discord server or on Twitter suggested that I reduce logging to the bare minimum so the Raspberry Pi’s memory card would last as long as possible. Those of you who’ve tinkered a bit with Raspberry Pi’s know their endemic curse: SD card data corruption. Sure, you can work around it by adding a standard SSD hard drive or a USB storage stick, but if you rely solely on the SD card, sooner or later you’ll run into trouble. This data corruption issue is easily solvable: you just need to have a spare memory card and a cloud backup of all your Home Assistant configurations, which you can do without a hitch using the plug-in that saves backups to Google Drive (more on that later), but when the card dies you’ll need a few minutes to run through this procedure, and in the meantime, the automations won’t work… neither will the lights… nor the sensors… nor the switches, in my case… nothing. It’s true the process is fast and almost seamless, the backup is PERFECT and you can restore it, reboot the Pi, and off you go — but those 10 minutes will feel very long if your wife is waiting with shampoo in her hair in the dark bathroom because the breaker tripped and the Pi took the opportunity to corrupt the SD card from the sudden power cut. Yes, this is a «live-cdote» as Buenafuente and Berto Romero would say. That’s why this week I decided to migrate Home Assistant from the Raspberry Pi 4 I was using to an Intel Nuc. The Intel Nuc is a small Intel computer with power consumption very similar to the Pi’s, but with a standard SSD hard drive that you can expand or swap out anytime, just like the RAM. Much more «scalable» than a Pi. Also, since it’s based on traditional processor technology (x86) rather than mobile processor technology (ARM) like the Pi, the overall performance and reliability of the system is much better. It’s not like there’s a dramatic speed difference since the Pi runs perfectly fine, but for some demanding tasks it can make a real difference… if I ever actually do a demanding task with this thing, lol.

Backing up Home Assistant

Many of you have told me you run Home Assistant in a virtual machine. This obviously simplifies the backup process a lot, since you can take a full system snapshot or copy the entire virtual machine and move it to another device. Zero hassle and a very simple process. But I don’t run Home Assistant in a virtual machine — that would make sense if I wanted to use the host system (in this case, the Nuc) for other virtual machines too… and in my opinion this introduces a new point of failure, since Home Assistant in that case is running on top of another vendor’s hypervisor, meaning operating system on top of operating system… and of course whether it’s VMWare, ProxMox, or whatever virtualization system you use, it has its own bugs and updates. Since in my case I don’t need the host system for anything else, I can skip that extra layer and install Home Assistant directly as the machine’s operating system. In this case, the best solution I’ve found for making backups is an add-on called Home Assistant Google Drive Backup, which gets installed in Home Assistant by adding the repository to the Home Assistant add-on store. No, don’t stress, it’s nothing complicated: go to Settings, Add-ons, Add-on Store, and from the three little dots in the top right go to Repositories and add the repository https://github.com/sabeechen/hassio-google-drive-backup. This add-on uses your Google account to automatically upload backups — there’s nothing else you need to do! Just give it your credentials and tell it how many backups to keep, which depends a bit on how much space you have… but each backup in my case takes up a bit over 200MB, so quite a few can fit. So before starting the migration, the first thing I did was create a new backup and sync it to Google Drive using this same add-on. Then you just need to restore it on the Nuc, and it sorts itself out after a couple of reboots — but I’ll get to that in a bit.

Installing Home Assistant on the Nuc

You won’t believe it, but this was the trickiest part! Home Assistant is available for the Intel Nuc platform, but it’s not as simple as downloading an ISO onto a USB drive, making it bootable, and kicking off the installation… On the Pi it really was that simple — in a few minutes it installed with no issues just by flashing the Home Assistant ISO onto an SD card — but with the Nuc there’s a bit more involved. First of all you need to disable Secure Boot, which tells the system which images are valid to boot from. Don’t worry, it doesn’t affect system security — this method was invented years ago so that someone with a Linux CD couldn’t boot into any system, access the drive, and format it to install that Linux. Imagine if you could do that with an ATM, and with your Linux already installed you could send messages to the dispenser to empty out the cash drawers. To be able to boot the Nuc and install an operating system image like Home Assistant, which is neither Linux nor Windows, you have to disable this protection. You just do it in the BIOS, that’s it, it’s very simple. And since I was already in the BIOS and plan on not restarting Home Assistant for many, many years, I took the chance to update the BIOS firmware as well, so I’d have the latest version available with all its drivers and bugs sorted out: To go through the whole installation process you’ll need 3 USB drives: the first for the Home Assistant image, the second for CloneZilla (the tool that will let us copy the image onto the SSD), and the third (optional) for updating the BIOS. Since there’s no point reinventing the wheel, here’s a really solid guide from Fertry Tech. Read it carefully because it’s a somewhat lengthy process, but if you follow it step by step you’ll be able to install Home Assistant on the Nuc without any issues.

Restoring the backup

Once you have Home Assistant installed on the Nuc, you just need to install the same backup add-on we mentioned earlier, download the backup we made a little while ago, and restore it. In my case, I took this moment to turn off the Pi (also taking advantage of my wife not being home) and plug into the Nuc the Zigbee USB dongle that all my devices connect to, since as you know I don’t use any manufacturer bridge (neither Aqara nor Hue) and all Zigbee devices connect to this dongle. I did this simply so there wouldn’t be any issues during the reboot, in case the Nuc started complaining about installed drivers or the devices said they couldn’t find the Zigbee USB dongle or some other nonsense. With the dongle plugged in, I rebooted the Nuc twice. Don’t ask me why, but the first time everything loaded up fine, but the devices weren’t able to connect to the Zigbee dongle. A moment of panic, thinking I was going to have to re-pair them one by one. Cold sweats, checking the clock and calculating how much time I had before my wife got back and noticed the entryway light didn’t turn on when she flipped the switch… But after the second reboot, they started connecting without any problems! For a few days I thought about buying another Zigbee dongle so I could run the installation in parallel and avoid this «cutover moment,» but then I realized that if I did that, I’d actually have to re-pair the devices with the new dongle anyway, so the fastest and best solution was the one I ended up going with.

Final location and going into production

And just like that… hahahaha. It’s true that the migration itself is really simple and intuitive: make a backup, install, restore the backup. The tricky part comes with installing the Nuc, which isn’t a simple process, at least not the way I did it. As I mentioned earlier, if you’re going to install Home Assistant on a virtual machine, the process is much simpler, but if you’re going to install Home Assistant directly as the operating system, then things get a bit more involved, and the best thing you can do is follow the article on the Fertry Tech blog I mentioned before. As you can see, I keep all the gadgets in a drawer under the TV — I didn’t like having them out on the furniture or in that typical nook people used to have for «putting the VCR,» I preferred to keep everything tucked away. So the only things I had to check were that the thing doesn’t overheat too much (it doesn’t, because the back of the drawer has a vent gap) and that Zigbee coverage reached the whole house properly. But as you know, Zigbee devices form a kind of mesh network and can hop between each other to reach the router — meaning the Zigbee device at the far end of the house isn’t connected directly to the antenna, but rather connects to another device, which connects to another, and another, and that last one connects to the Zigbee antenna. So I haven’t had any coverage or delay issues. And no, don’t worry, Home Assistant hasn’t become my new shepherd. I’m really looking forward to going back to HomeKit, especially now that with iOS 16 the Home app is going to support Matter! But it’s true that with Home Assistant you can do a lot more things (not all of them simple, granted), and for now it’s working really well for me, with no delays and no major issues. The next thing I want to focus on is the aesthetic side, since up until now I hadn’t given it any thought — I just left it looking however as long as everything worked — but now I want to explore the customization options and see if it can end up being as nice-looking as Apple’s Home app.