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Upgrading Our Home Assistant Server

Home_Assistant_Logo.300For our first couple of years using Home Assistant the software was hosted on a Raspberry Pi 4B with 4GB of memory and a 32GB High-Endurance micro SD card. To get started, the Pi4 was cheap and readily available. It had enough power to do most things. My initial requirements were very simple, so not a lot of CPU requirement. The RPi4 was an admirable, accessible solution at the time.

However, times change. I get silly new ideas that I’d like to try. For example, it would be interesting to integrate our surveillance cameras with HA. Perhaps with some AI-based object detection.

Also, in post-COVID times, RPi4 have become hard to get, and much more costly. They’re currently running about 3x normal price, if you can get them. Thus, it could be useful to reclaim the RPI4 from HA duty, if another suitable host could be found.

HP T620 Thin Client

Of course another host could be found. In fact, I was able to procure a recycled HP T620 thin client on Ebay for just $35 delivered! That’s cheaper than a RPI4 with a case & power supply.

HP T620 FrontThe T620 has the following:

  • AMD GX-415GA Quad Core CPU @ 1.5 GHz
  • 8 GB RAM
  • 16 GB mSATA SSD (SanDisk)
  • 1 GB Ethernet
  • 2 Display Ports
  • 6 USB ports
  • 2 available internal M.2/mSATA slots
  • No operating system
  • 65 watt external power supply

Not exactly gaming specs, but vastly more powerful than a RPi4. Still a relatively compact, fanless design that satisfies my requirement for silence.

HP T620 BackNon-plussed This Time

I’ve had a T620 Plus inhouse for a while. The “Plus” denotes the variant with a slightly larger chassis, providing one available PCIe slot. Populated with a dual-ported Intel network card, and running pfsense, this is our core router.

Home Assistant Backups

My Home Assistant installation is set to make a regular weekly backup image. Further, it makes a backup automatically every time an update is installed.

My plan was to migrate to the T620 by restoring a recent backup made using the RPi. Since both run HAOS, the backup should be portable across platforms, despite the different CPU types.

The migration process began by logging into Home Assistant on the RPi and downloading the last backup. Then I could power down the RPi.

Installation

Installation of Home Assistant on the T620 took just a few minutes. The T620 has a tool-less case. Just unclip the back panel, release a small locking lever, and slide off the top. Once looking inside the M.2 & mSATA slots are obvious.

Just look at the heatsink in the top of the picture below. Good heat sinks are key to a reliable, fanless design.

HP T620 Internals 1200px

To begin, I removed the existing SSD, mounting it in an external USB 3 sled so it could be connected to my desktop. Following the HA Generic x86 instructions, I used Balena Etcher to flash the x86 image to the drive.

Returning the SSD to the T620, I connected a monitor and Ethernet, then powered it up. The boot process appeared as expected, eventually coming to stop at a login prompt.

Configuration

The device initially obtained an arbitrary IP address from the DHCP server in our router. As is my habit, I set the router to always assign the same IP address to its MAC address. Power cycling the T620, it took up the specified IP address, finding a home where the RPi once lived on our network. That made my browser shortcuts and Home Assistant mobile app settings valid once again.

The initial login to a new Home Assistant installation prompts for creation of a new set of credentials, but also allows the upload of a backup created previously. Selecting the tar file exported from the RPi for upload, the configuration of the new installation was wholly automated.

HAOS Initial Login Screen

After a few minutes I found myself logged into the familiar, if uninspired, Lovelace web UI that I had created previously.

HAOS Lovelace Main Page

Migration Results

I’m happy to report that almost all my device integrations, automations and actions migrated successfully. Philips Hue, Lutron Caseta dimmers, Flume water meter, Shelly power metering, Nexia thermostat, Sensibo control of office AC unit, TP-Link smart outlets and Logitech Media Server…all available and working as expected.

That’s really remarkable.

With One Exception

There’s only one thing that did not migrate. The NUT extension used to monitor the status of my Eaton UPS seems to have lost contact with the NUT server.

The NUT server is installed on the Raspberry Pi 400 that primarily acts as our music server. The RPi 400 is physically close to the UPS, which made it a convenient way to connect to the USB monitoring port.

This is small thing. Not a high priority. I will revisit this another day to seek a resolution.

Summary

In about an hour, and with very little effort, I was able to migrate our Home Assistant server from the RPi4 to the T620. In the coming days I’ll experiment with integrating our IP cameras and seek to restore the UPS monitoring.

P.S. – I’m a huge fan of power-over-Ethernet. Our Raspberry Pi devices, including the old HA server, are all powered from the network. The T620 can’t be powered that way. But since it’s in the very same rack as the switch and the UPS, it doesn’t matter. It’s directly connected to the Eaton UPS.

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