James O'GormanSep 13, 2025

I want to migrate Home Assistant from a container on an old NUC to HAOS in a VM on a new machine.

Thought it should be easy: take a backup in HA, download it, restore it. But fuck me, with the default settings HA takes nearly 2 hours to create a backup of my (admittedly large) data. I'm not going to accept 2+ hours of data loss.

Turns out they now encrypt backups by default (good, probably). Turning that off I can reduce to 15 mins, but looks like it's slowed down by a single-threaded gzip.

Show threadJames O'GormanSep 13, 2025

Home Assistant, I know I can do better than you.

Let's try streaming a raw tar file over the network to a machine that can compress faster.

On the HA machine:

time tar -cvf - --exclude='backups/*.tar' --exclude='*.db-shm' --exclude='*.log' --exclude='*.log.*' --exclude='tts/*' * | nc -Nl 2222

And on my M2 Pro Mac:

time nc sadpunk 2222 | gzip > ha-manual.tar.gz

9:28.20. Better than the 15 mins.

Show threadJames O'GormanSep 13, 2025

But we can do better! Let's give it some pigz.

time nc sadpunk 2222 | pigz > ha-manual.tar.gz

3:44.93. That'll do nicely. Down from nearly 2 hours to just under 4 minutes.

Show threadJames O'GormanSep 13, 2025
lol Home Assistant. Now the new system fails to import the backup. The web UI returns a 500 after a while. I guess I’m really going to be doing this the hard way then.
Show threadJames O'GormanSep 13, 2025

Jesus fucking christ WHAT THE FUCK, HOME ASSISTANT.

So, the backup needs to be a tarball containing a file called backup.json (metadata) and the gzipped tarball I made.

The upload of the backup failed because HA is expecting the tarball to contain ./backup.json and I added it just as backup.json. What the actual fuck.

Show threadJames O'GormanSep 14, 2025

I've written up the full saga: https://pub.jamesog.net/3lysnfelse22w

This is published on https://leaflet.pub/ which uses ATproto to store your posts. It's pretty nice. Much nicer than my Hugo setup that constantly breaks, anyway.

Adventures in migrating Home Assistant between devices - james(bl)og

Moving from HAOS to a container install and back to HAOS

Show threadFred MoyerSep 14, 2025
@jamesog that’s quite the migration effort. I considered doing something similar for replacing my ubiquiti gateway with the newer one, then I just yeeted the old one and plugged everything into the new one. 30 minutes later everything was back online.
Show threadJames O'GormanSep 14, 2025
@phredmoyer In some ways I have regrets about buying in to the Home Assistant ecosystem. I hate large Python software projects and I wish it was easier to migrate the data to a proper TSDB. Probably I could have started from scratch and been happy enough having the data that's also in Prometheus, but it's useful to have HA have all data so I can review how solar PV has been working year-on-year.
Show threadʙʙʀᴀᴅʟᴇy
@jamesog I always treated my Home Assistant container as being close to ephemeral. Every 6-12 months I would just copy out the automations/config yamls (which I stored under version control anyway) then drop that into a new installation. I was never bothered about historical data in HA since I scraped HA's Prom exporter separately to drop the entities that I had no interest in (most of them).
Having said all that I still haven't rebuilt my HA after moving house 3 years ago so 🤷
Sep 14, 2025 at 5:56pmWeb
Show threadJames O'GormanSep 14, 2025
@29821632 I've got it all in Prometheus too, but there's some places where HA's more useful for looking at the data, mostly on the Energy dashboard. It's a bit tricky to reproduce that in Grafana. I guess HA keeps its own aggregations too, which I probably need to create recording rule for in Prom
Show threadʙʙʀᴀᴅʟᴇySep 14, 2025
@jamesog Ah that's fair, especially for smart energy monitoring integrations. My HA was purely for controlling things, either manually with a toggle/widget or a chain of integrations, so for that I only needed the instantaneous data. Main integration I had was presence/absence detection using phone MAC addresses appearing on the Unifi wifi controller which would arm/disarm the Blink cameras. It worked well but the database would get massive, hence me blatting it quite frequently.