What the heck: why doesn't home assistant use usb drives?

capstan1 · August 19, 2020, 4:13am

My what the heck for a long time: using usb drives easily inside home assistant.
Dying SD-cards of RasPis is a long time discussed issue here. While it’s working okay for me with better cards, I’m very concerned about it dying.

However, there is no option of putting parts of the System on an SD card on my raspberry pi3 via thts reliably working. Getting usb drives available to home assistant to write files to and/or having an easy way of installing it to usb would be great.

What I want the most: option to put the database (for history and so on) on an USB drive.

nickrout · August 19, 2020, 4:13am

But you can.

capstan1 · August 19, 2020, 4:14am

Then please point me to an easy solution that let me move my database to an usb drive on Home Assistant (former Hass.io)

nickrout · August 19, 2020, 5:27am

~~https://www.cribbstechnologies.com/index.php/home-assistant/moving-home-assistant-logs/~~

edit: frenck says no

capstan1 · August 19, 2020, 4:26am

Thanks! Gonna try that out! In none of the threads in here this was pointed out.
What I’m still wondering: this really works with home assistant? (hass.io)

nickrout · August 19, 2020, 4:41am

I think so, but there is one way to find out.

Why not just boot the whole system off usb?

capstan1 · August 19, 2020, 5:10am

Because I didn’t find a solution that doesn’t:
- Requires using the development build
- require a raspberry pi 4
- use the supervised install - that’s no longer officially supported

That’s what I wanted to say: maybe there is a way (or even 10 ways) but they are complicated. It should be: plug in your usb, get it recognized by Hass.io, go to settings and move database to usb. (I’d be okay changing the path via yaml, but UI would be nicer if we start changing things)

frenck · August 19, 2020, 5:24am

Please, do not use that method , you might get into trouble later on.

However, that said, the Home Assistant Operating System does have support for things like this.

github.com

home-assistant/operating-system/blob/c6a1e668f4d26bd632e39cf5c4cc813481bcfac6/Documentation/partition.md

# Partition

The partition layout is a bit different than for regular setups. We prefer GPT, if possible. With SoCs which don't support GPT, we use the hybrid GPT. For more details about this topic, please refer to the [development](development.md) documentation.

The system is designed to have as less as possible write operations on the storage media. Which means that we have basically only write during the OTA update and 5-6 times per week on the overlay part. The data partition is having I/O. This is the reason which is should be run on a different drive.

A visual representation looks like this:

```text
-------------------------
|       Bootloader      |
-------------------------
|       Kernel A        |
-------------------------
|       System A        |
|                       |
-------------------------
|       Kernel B        |
-------------------------
|       System B        |

This file has been truncated. show original

You can actually move your data over to an external harddrive using the datactl command. E.g.,

datactl move /dev/xxx

(you need to be patient after the first reboot, but it will work )

nickrout · August 19, 2020, 5:26am

I must say that this is the first time I have seen this! Thank you.

nickrout · August 19, 2020, 5:27am

The supervised install is officially supported.

capstan1 · November 8, 2020, 6:31pm

@frenck: Thanks for your input!
Had time to try it out today. How can I check if it really worked?
Tried to plug out the usb-drive and booting and HA still booted up. What can I do to see logs while moving the data to see what went wrong?

LoloPicolo · December 16, 2020, 10:10am

hi @frenck I’ve done the datactl move /dev/sdb action and confirmed with yes. my HA has been rebooted and works fine. how can i see that data have been transfered ? in System Metrics, Used space has not changed. Thanks for your support and great tool

capstan1 · January 15, 2021, 5:00pm

If you are still wondering: you can use

systemctl status mnt-data.mount

It should say that it’s enabled and which drive was mounted.