[UPDATE 2020-10-14 by @Jpsy ]:
Added instructions to update HA OS through CLI.
[UPDATE 2020-10-18 by @Jpsy ]:
More details added on installing and using Raspberry OS to update the EEPROM firmware.
[UPDATE 2020-10-31 by @Jpsy ]:
Added warning to NOT use HA OS version 5.4.
Added hint that Raspberry Pi Imager can be used to update EEPROM.
[UPDATE 2020-12-08 by @Jpsy ]:
Added warning to NOT use the snapshot restore feature of the first login screen.
All HA OS version references updated to v5.6.
[UPDATE 2021-01-08 by @Jpsy ]:
SSD boot and Pi4 with up to 8GB are now officially supported.
Updated adaptor recommendation from ELUTENG to StarTech.
Added hint to and recommendation for ODROID-N2+ and Home Assistant Blue.
Added info about a sufficient power supply.
Added info about different boot EEPROM versions.
All HA OS version references updated to v5.10.
Added warning about HA OS versions 5.6 to 5.8 with boot EEPROM update code.
Updated references to current stable boot EEPROM to
Added general warning about Pi4 boot firmware problems and link to release list.
Added warning about USB3 interference with Zigbee, Zwave, …
Added section “Compilation of facts” to sum up details and infos.
[UPDATE 2021-01-11 by @Jpsy ]:
raspi-config menu item sequence updated. Thanks to @Egon for the info.
Reference added to Intel’s document on USB3 interference with WLAN, Zigbee, Zwave, Bluetooth… Thanks @tldp, @KCYeoh and all the others who mentioned it.
RPi 3 for HA is dead!
I finally found that the lags and hangs of HA on my RPi 3b were the result of too many add-ons that quickly filled up the 1 GB of memory. I considered switching to a NUC or an AMD 4500U based system. But I love the low power consumption of the Pis and their small carbon footprint. So I decided to try the current upper end of the Pi spectrum:
Long live HA on Raspberry Pi 4b
…with (up to) 8GB of memory and booting directly from SSD !
You may want to consider an ODROID-N2+ with 4GB instead of a new Pi. The N2+ is actually recommended by the HA devs.
Before we begin I want to make you aware of the fact, that the HA developers recommend another hardware: The ODROID-N2+. There is even a beautiful HA branded casing available for it, bundled with everything that you need to start with. See Home Assistant Blue. I don’t know if the ODROID has any of the compatibility issues in relation to USB adaptors that the Pi 4 has (and that we will cover below). But if you have not yet made your decision and ordered your hardware I honestly recommend you go with the HA Blue package. The only reasons why I stay with the Pi4 8 GB is that I have it running (with no problems) and that it has 8 GB while the ODROID has only 4 GB.
But this guide is about the Pi 4b and you are here because you looked for it. So let’s get started…
On the way from Pi3 to Pi4 and from SD to SSD I faced some problems:
The 8GB version is not yet officially supported by HA. The full SSD boot of HA is also not yet officially available for the Pi 4.
- The SSD boot on the Pi4 is still full of pitfalls. This is not a Home Assistant problem but a Raspberry Pi problem. Especially the EEPROM bootloader firmware does not work with all available USB-to-SATA adaptors on the market.
Fortunately these problems can be solved and the resulting system works flawlessly and is extremely fast! The 8GB memory provides HA with enough space to run many add-ons and a long data history (30 days in my setup) without starting to swap or choke. And there is always plenty of in memory buffer and cache available to keep DB accesses really fast.
The following instructions will work for all version of Pi 4b – 1, 2, 4, 8 GB. You may actually have some more options with the versions below 8 GB (like using the 32bit version of HA). But I still recommend the 8 GB version as it will surely keep you happy for a longer time to come.
So let’s go in there, step by step:
Use the right SATA to USB3 adaptor
This is propably the one most important step for your success. Not all available SATA adaptors are working on the RPi 4. This is not a HA problem but a generic RPi issue. Please see this very helpful blog posting of James A. Chambers. It contains lists of working and non-working adaptors. I started myself with a Sabrent adapter based on a JMicron JMS583 bridge chip which gave me quite some trouble. I.e. it only worked reliably when connected to one of the USB2 ports – not on USB3. I then switched to an ELUTENG adaptor that works like a charm for me and was cheap too.
Unfortunately it turns out that there are two versions of the ELUTENG that look nearly identical but use different chip sets. One of them only works on USB2. So if you are looking for a working solution my current recommendation is that you use either of these two adaptors:
- StarTech 2.5″ SATA to USB 3.1 Adapter
- StarTech 2.5″ SATA to USB 3.0 Adapter
Use a sufficient power supply
The second most important factor for your success is to use a power supply that is capable of driving your Pi 4 and (!) your SSD. Nothing will give you more headaches than an insufficient power supply. You system will stall when you don’t expect it and you will not understand why!
At least use the original Pi 4 power plug with 3 Ampere. If you can get a good quality supply with 3.5 Amps or more: Use it!
Alternatively you can use a powered USB hub or casing to give your SSD a dedicated power supply. I personally don’t like that idea because a second power plug creates additional energy losses and is another item that can break. But it is still much better than an unstable supply.
Use Raspberry OS to update the EEPROM firmware
RPi 4 has a boot EEPROM (which RPi 3 did not!). You have to update that EEPROM to the latest firmware (2020-12-11 or higher) which enables USB boot. To update the EEPROM you have to temporarily install Raspberry OS. I used an SD card for this. If you want to learn more you can read the Raspberry Pi docs but we will go through all the steps here in detail.
(Hint: There seems to be a simpler way to update the EEPROM firmware through Raspberry Pi Imager instead of Raspberry Pi OS. I did not try that option. If you want to go for it, check this comment below.)
First download Raspberry OS and burn it onto an SD card. You do that using Raspberry Pi Imager. Versions for Windows, Mac and Ubuntu are available here.
A) If you have a keyboard, mouse and monitor attached to the Pi
This is my recommendation but you will need a micro-HDMI adaptor cable for that, which you might not have. If you do, simply start your Pi with that SD card and monitor/keyboard/mouse attached. Go through the initial setup process.
When all is done open a terminal window.
B) If you have NO monitor attached to the Pi:
Prepare to access Pi’s shell through SSH. To do so you simply add an empty file called “ssh” (no file extension) to the root of the boot partition on the SD card. You should have two partitions. The first (and smaller) one is the boot partition. Place the file there.
Now start your Pi with that SD card and access the Pi’s shell through SSH from another device on the network.
The ssh-file on the boot partition is deleted on first boot, so you will loose SSH access when you reboot. To keep SSH access launch raspi-config now from the command line:
Interfacing Options »
Update the boot EEPROM firmware
This is done by telling the OS to use the latest stable version for all updates and then simply rebooting:
Edit the rpi-eeprom-update file and change the FIRMWARE_RELEASE_STATUS from “critical” to “stable”:
sudo nano /etc/default/rpi-eeprom-update
Change the file, save and exit nano. Then…
sudo apt update sudo apt full-upgrade sudo reboot
Let the system reboot. The EEPROM should be updated automatically during the boot process.
Check the EEPROM version
This should now report at least firmware 2020-12-11 or higher.
The boot EEPROM development of RPi 4 is currently a mine field!
It is possible that your USB-to-SATA adaptor contains a chipset that is not (yet) compatible with the current boot code. There are many problem reports. The StarTech adaptor mentioned above should steer you clear of that. But there is no guarantee. Some users have better luck with older (!) boot EEPROM versions. See the Pi4 bootloader EEPROM release notes for a list of stable and beta versions.
Use raspi-config to set boot config to SSD boot
Go through these menu items:
when the system asks to “Reset boot ROM to defaults” select No (!!!) to use the latest boot ROM.
We are now done in Raspberry Pi OS. I recommend that you keep that SD card with RPi OS! You can always use it later for more EEPROM updates. It is also very helpful to access your HA SSD and salvage your config and data in case HA should refuse to start some day!
Flash Home Assistant to SSD
Now download the latest Home Assistant 5.x OS from here:
Look for the latest “Release 5 build X (Stable)” (5.10 at the time of this writing).
Open the “Assets” panel under the list of changes to see the downloads.
Find the image hassos_rpi4-64-5.X.img.gz - make sure it is rpi4 (not rpi3) and 64 bit.
AFAIK the 8 GB Pi won’t run with the 32 bit version.
WARNING: Do NOT use HA OS 5.4! There was an issue with that version that affected some but not all RPi4s. (See discussions below.) Also do NOT use HA OS version 5.6 to 5.8. These contained their own boot EEPROM update code that flashed a beta version into the EEPROM. This approach was removed in 5.9.
Use Balena etcher or a similar tool to flash the image onto your SSD.
(Yes Balena can flash to SSD, not only SD!)
Start Home Assistant
Plug the SSD into the Pi, take out any remaining SD card and boot.
Check http://homeassistant:8123 on your network or use Port 8123 with the IP that your router’s DHCP has assigned.
It helps to follow the boot process on a monitor that is directly attached to the Pi. You will need a micro-HDMI adapter cable for that.
When the initial login screen comes up DO NOT use the snapshot restore feature of this screen. There have been multiple reports that installing a snapshot from here does not work and may even ruin your virgin HA installation. There seems to be some incompatibility of snapshots created with other HA OS versions. Instead define your new admin user and do a fresh first start. Then go to Supervisor » Snapshots and use the dot menu in the upper right corner to upload and restore your snapshot.
When you are waiting for the initial login screen you may experience extremely long boot times (>10 min). If this happens to you you have multiple options:
- Check the section “Use the right SATA to USB3 adaptor” above. Chances are that you are using a non-compatible SATA to USB3 adaptor or casing. Try the StarTech that I recommended above.
- Try to connect your SSD through a USB 2 port (black) instead of a USB 3.0 port (blue). I know it sounds strange, but please really do! If this works for you, it may be your best option. Although USB 2 is much slower than USB 3.0 you will get a very fast system. But if option 2. works for you you should also reconsider option 1. It is very likely that your adaptor or casing is the culprit.
- Check if your SSD casing or your SATA to USB adapter is based on a JMicron JMS583 bridge chip. There is a firmware update for this chip that solves the problem. For Sabrent devices the update for all affected devices can be found here. But I also remind you that my own Sabrent adaptor never really worked for me. Read 1. again!
- Make sure your power supply is capable of feeding your Pi and (!) your SSD.
Check the section “Use a sufficient power supply” above.
The good news after that final trouble is:
You are done! Enjoy your new HA installation.
A warning about USB3
USB3 signal frequencies may interfere heavily with WLAN, Zigbee, ZWave, Bluetooth, enOcean!
Use USB extension cables (male-to-female) to place your radio sticks away from the Pi.
Connect your USB2 radio sticks to USB2 ports not to USB3. (Well, actually the USB3 ports should not really interfere as long as they run in USB2 mode, but better don’t push your luck).
Read Intel’s document on USB3 interference to understand the details and how you can place and shield your devices.
Update the DEV version of Home Assistant OS
Nerd info on HA OS. This was mainly insteresting for early adopters while the 5.x OS was still under development:
If a new 5.x DEV version of HA OS becomes available you may find that the Supervisor menu in the HA frontend does not offer you the update, even if you have switched to the beta channel. This is due to the fact that only stable and beta versions are offered here, not dev versions. But you can update your OS at any time using the command line interface (CLI) of HA. To do so you need SSH shell access to HA. There are multiple add-ons that expose SSH (my recommendation: Frenck’s great “SSH & Web Terminal”).
In the shell you can use the following command to update your OS to a defined version:
ha os update --version 5.10
Try this command before and after the update to get some system info:
ha os info
Compilation of facts
This is a compressed collection of facts that are spread throughout the guide above.
Might be helpful for trouble shooting.
- HA OS versions 5.0 to 5.5 did NOT change the boot EEPROM
- HA OS versions 5.6 to 5.8 DO change the boot EEPROM to version 2020-10-28 - BETA. This was beta but considered the better solution for many users because it solves reboot hangs for many drives.
- HA OS versions since 5.9 do NOT change the boot EEPROM any more to give back control to the user.
- There are multiple generations of “stable” boot EEPROM versions available (see release list).
But even in the RPi GitHub repo there are plenty of issue reports. So I suggest that if you found an EEPROM version that is working for you, you do NOT upgrade the EEPROM at this time.
- All in all it seems recommendable right now to manually try several stable boot EEPROM versions and avoid HA OS versions 5.6 to 5.8 because they will overwrite the EEPROM on their own. Start with the latest stable EEPROM version as described in the guide.
- There seem to be problems with some adapter chip sets when switching to UAS (USB Attached SCSI, UAS or UASP) during Linux system startup. But I still have to gather information about that.
- RPi4 with 1, 2, 4 GB behave slightly different from 8 GB on a reboot. All do a USB power off but the 8 GB version does it much longer. If your Pi with up to 4GB hangs on reboot try to really power off/on the system.
- Make sure your RPi power supply is sufficient to power both your Pi AND your SSD. Better use the original RPi4 power supply with 3 Ampere output. If you find a quality supply with more than 3 Amps: use it.
- USB3 signal frequencies may interfere heavily with WLAN, Zigbee, ZWave, Bluetooth, enOcean. Use a male-female USB adapter cable to get your radio sticks away from the Pi. Connect your sticks to USB2 not 3.