---
title: >-
  The 70GB ghost: Hunting Down Mysterious Storage Usage in HAOS
date: 2026-01-09 13:00:00
modified: 2026-05-23 08:57:00
lang: en
authors: Piotr Pelica
url: https://pelica.net/en/the-70gb-ghost-hunting-down-mysterious-storage-usage-in-haos
tags:
 - technology
 - home-assistant
 - self-hosting
 - homelab
status: published
---

# The 70GB ghost: Hunting Down Mysterious Storage Usage in HAOS

**TL;DR:** A failed update left old Frigate recordings in `/data/emergency`, silently eating ~70 GB until cleaned up.

***

Thursday evening, new Home Assistant update, everything is cool… except it’s not.

Supervisor complains: Data disk is running low on free space.

media[1858]

I thought "that’s weird, 128 GB of space should be plenty", but turns out it’s not. I go to System → Storage and see “System: 98.9 GB”.

What? How?

I went ahead and checked the usual culprits, but the database was 1.9 GB, addons were barely 7 GB, backups were kept on an external system… So none of that.

So I checked the supervisor itself.

I made sure that the SSH add-on had protection disabled. I first tried the documented `login` approach, but it dropped me into the add-on container rather than the host. Since `docker ps` was available, I attached directly to the Supervisor, which I knew would expose `/data`:

```bash
docker exec -it hassio_supervisor bash
```

In there, quick `du -sh /` allowed me to confirm how much space it uses:

```bash
826c72cb369e:/# du -d 1 -h | sort -h
0       ./dev
0       ./proc
0       ./sys
4.0K    ./home
4.0K    ./mnt
4.0K    ./opt
4.0K    ./srv
4.0K    ./tmp
16.0K   ./media
52.0K   ./command
56.0K   ./root
56.0K   ./var
288.0K  ./sbin
832.0K  ./lib
1.1M    ./run
1.3M    ./etc
1.7M    ./bin
5.5M    ./package
353.9M  ./usr
95.8G   ./data
96.2G   .
```

Ah. 95.8 GB in `/data`. Okay. What’s there?

```bash
826c72cb369e:/data# du -d 1 -h | sort -h
8.0K    ./core
12.0K   ./dns
12.0K   ./tmp
16.0K   ./.mounts_credentials
68.0K   ./media
80.0K   ./audio
84.0K   ./cid_files
140.0K  ./ssl
252.0K  ./apparmor
165.6M  ./addon_configs
169.3M  ./share
2.6G    ./homeassistant
4.8G    ./backup
7.1G    ./addons
9.3G    ./mounts
71.6G   ./emergency
95.8G   .
```

Ah. Okay. So what’s that `emergency`? Turns out during failed or interrupted updates, the Supervisor copies data there as a rollback safety net. Normally it’s cleaned up automatically. In my case, it wasn’t - and it contained old Frigate recordings **dating back to 2023**.

Cue the facepalm.

Since the system had booted normally and wasn’t in recovery mode, it was safe to remove. Rather than removing the entire emergency directory, I deleted just the Frigate data inside it:

```bash
rm -r /data/emergency/frigate
```

And that brought the system usage to normal, at around 26 GB.

So, there it is.