Can't write new backup file: [Errno 12] Out of memory

[estevez-dev]

Describe the issue you are experiencing

Once every couple of weeks, I must reboot the Home Assistant host machine to resolve this issue.

Automated backups are not uploaded to the network storage (SMB), while stored locally successful.

Here are my disk metrics:

What type of installation are you running?

Home Assistant OS

Which operating system are you running on?

Home Assistant Operating System

Steps to reproduce the issue

1. Configure SMB network storage for backups
2. Configure automated backups
3. Wait for a couple of weeks

Anything in the Supervisor logs that might be useful for us?

2026-08-27 05:32:56.009 INFO (MainThread) [supervisor.backups.manager] Backup c268233c starting stage app_repositories
2026-08-27 05:32:56.010 INFO (MainThread) [supervisor.backups.manager] Creating new partial backup with slug c268233c
2026-08-27 05:32:56.014 INFO (MainThread) [supervisor.backups.manager] Backup c268233c starting stage home_assistant
2026-08-27 05:32:56.019 INFO (MainThread) [supervisor.homeassistant.module] Backing up Home Assistant Core config folder
2026-08-27 05:33:02.117 INFO (MainThread) [supervisor.homeassistant.module] Backup Home Assistant Core config folder done
2026-08-27 05:33:02.120 INFO (MainThread) [supervisor.backups.manager] Backup c268233c starting stage apps
2026-08-27 05:33:02.128 INFO (MainThread) [supervisor.apps.app] Building backup for app 5c53de3b_esphome
2026-08-27 05:33:02.147 INFO (MainThread) [supervisor.apps.app] Finish backup for app 5c53de3b_esphome
2026-08-27 05:33:02.380 INFO (MainThread) [supervisor.apps.app] Building backup for app core_mariadb
2026-08-27 05:34:20.045 INFO (MainThread) [supervisor.apps.app] Finish backup for app core_mariadb
2026-08-27 05:34:20.288 INFO (MainThread) [supervisor.apps.app] Building backup for app core_mosquitto
2026-08-27 05:34:20.307 INFO (MainThread) [supervisor.apps.app] Finish backup for app core_mosquitto
2026-08-27 05:34:20.317 INFO (MainThread) [supervisor.apps.app] Building backup for app a0d7b954_vscode
2026-08-27 05:34:21.487 INFO (MainThread) [supervisor.apps.app] Finish backup for app a0d7b954_vscode
2026-08-27 05:34:21.495 INFO (MainThread) [supervisor.apps.app] Building backup for app 45df7312_zigbee2mqtt
2026-08-27 05:34:21.511 INFO (MainThread) [supervisor.apps.app] Finish backup for app 45df7312_zigbee2mqtt
2026-08-27 05:34:21.524 INFO (MainThread) [supervisor.apps.app] Building backup for app 9074a9fa_cloudflared
2026-08-27 05:34:21.538 INFO (MainThread) [supervisor.apps.app] Finish backup for app 9074a9fa_cloudflared
2026-08-27 05:34:21.550 INFO (MainThread) [supervisor.apps.app] Building backup for app core_piper
2026-08-27 05:34:21.568 INFO (MainThread) [supervisor.apps.app] Finish backup for app core_piper
2026-08-27 05:34:21.605 INFO (MainThread) [supervisor.apps.app] Building backup for app core_zwave_js
2026-08-27 05:34:23.737 INFO (MainThread) [supervisor.apps.app] Finish backup for app core_zwave_js
2026-08-27 05:34:23.746 INFO (MainThread) [supervisor.apps.app] Building backup for app a0d7b954_nut
2026-08-27 05:34:23.762 INFO (MainThread) [supervisor.apps.app] Finish backup for app a0d7b954_nut
2026-08-27 05:34:23.764 INFO (MainThread) [supervisor.backups.manager] Backup c268233c starting stage folders
2026-08-27 05:34:23.766 INFO (SyncWorker_2) [supervisor.backups.backup] Backing up folder ssl
2026-08-27 05:34:23.838 INFO (SyncWorker_2) [supervisor.backups.backup] Backup folder ssl done
2026-08-27 05:34:23.841 INFO (SyncWorker_1) [supervisor.backups.backup] Backing up folder share
2026-08-27 05:34:23.847 INFO (SyncWorker_1) [supervisor.backups.backup] Backup folder share done
2026-08-27 05:34:23.849 INFO (SyncWorker_6) [supervisor.backups.backup] Backing up folder media
2026-08-27 05:34:23.854 INFO (SyncWorker_6) [supervisor.backups.backup] Backup folder media done
2026-08-27 05:34:23.856 INFO (MainThread) [supervisor.backups.manager] Backup c268233c starting stage supervisor_config
2026-08-27 05:34:23.856 INFO (SyncWorker_5) [supervisor.backups.backup] Backing up supervisor configuration
2026-08-27 05:34:23.861 INFO (SyncWorker_5) [supervisor.backups.backup] Backup supervisor configuration done
2026-08-27 05:34:23.863 INFO (MainThread) [supervisor.backups.manager] Backup c268233c starting stage finishing_file
2026-08-27 05:34:23.867 INFO (MainThread) [supervisor.backups.manager] Creating partial backup with slug c268233c completed
2026-08-27 05:34:23.892 INFO (MainThread) [supervisor.api.backups] Downloading backup c268233c
2026-08-27 05:42:57.852 ERROR (MainThread) [supervisor.api.backups] Can't write new backup file: [Errno 12] Out of memory

System information

System Information

version	core-2026.7.4
installation_type	Home Assistant OS
dev	false
hassio	true
docker	true
container_arch	aarch64
user	root
virtualenv	false
python_version	3.14.6
os_name	Linux
os_version	6.18.39-haos
arch	aarch64
timezone	Europe/Kyiv
config_dir	/config

Home Assistant Cloud

logged_in	false
can_reach_cert_server	ok
can_reach_cloud_auth	ok
can_reach_cloud	ok

HACS

GitHub API	ok
GitHub Content	ok
GitHub Web	ok
HACS Data	ok
GitHub API Calls Remaining	5000
Installed Version	2.0.5
Stage	running
Available Repositories	4044
Downloaded Repositories	7

Home Assistant Supervisor

host_os	Home Assistant OS 18.2
update_channel	stable
supervisor_version	supervisor-2026.07.5
agent_version	1.10.0
docker_version	29.6.2
disk_total	113.9 GB
disk_used	27.1 GB
nameservers	192.168.1.1
healthy	true
supported	true
host_connectivity	true
supervisor_connectivity	true
ntp_synchronized	true
virtualization
board	odroid-n2
disk_life_time	0 %
supervisor_api	ok
version_api	ok
installed_addons	ESPHome Device Builder (2026.7.4), MariaDB (3.0.1), Mosquitto broker (7.1.0), Studio Code Server (6.0.1), Zigbee2MQTT (2.13.0-1), Cloudflared (7.0.13), Piper (2.3.2), Z-Wave JS (1.7.0), Network UPS Tools (0.18.0)

Dashboards

dashboards	3
resources	3
views	9
mode	storage

Network Configuration

adapters	lo (disabled), end0 (enabled, default, auto), hassio (disabled), docker0 (disabled), veth9c6b991 (disabled), veth3881115 (disabled), vethc9e9ff0 (disabled), veth9bf3765 (disabled), vethb5c6722 (disabled), vethbeaa79d (disabled), vethcbfd333 (disabled), veth3223fbc (disabled), veth7263418 (disabled), veth12a6beb (disabled), veth4b6bf1e (disabled), veth10782b3 (disabled)
ipv4_addresses	lo (127.0.0.1/8), end0 (192.168.1.22/24), hassio (172.30.32.1/23), docker0 (172.30.232.1/23), veth9c6b991 (), veth3881115 (), vethc9e9ff0 (), veth9bf3765 (), vethb5c6722 (), vethbeaa79d (), vethcbfd333 (), veth3223fbc (), veth7263418 (), veth12a6beb (), veth4b6bf1e (), veth10782b3 ()
ipv6_addresses	lo (::1/128), end0 (fe80::f122:5641:1014:6728/64), hassio (fd0c:ac1e:2100::1/48, fe80::388a:83ff:fe6b:191a/64), docker0 (fd3b:83a5:750a::1/64, fe80::7c08:13ff:fe67:b9b0/64), veth9c6b991 (fe80::ec42:afff:fe32:ca45/64), veth3881115 (fe80::7864:c1ff:fe70:662e/64), vethc9e9ff0 (fe80::acb8:b2ff:fe03:7f8d/64), veth9bf3765 (fe80::dca5:e6ff:fe8a:bd44/64), vethb5c6722 (fe80::60b6:6cff:fe4d:46b6/64), vethbeaa79d (fe80::468:b9ff:fe96:81d1/64), vethcbfd333 (fe80::386f:85ff:fe85:6c74/64), veth3223fbc (fe80::5c47:3cff:feab:bf7/64), veth7263418 (fe80::b4b9:bff:fe72:6999/64), veth12a6beb (fe80::d082:afff:fec9:c23d/64), veth4b6bf1e (fe80::e08c:81ff:fe84:5fa0/64), veth10782b3 (fe80::bc67:3aff:feef:e106/64)
announce_addresses	192.168.1.22, fe80::f122:5641:1014:6728

Recorder

oldest_recorder_run	May 28, 2026 at 09:24
current_recorder_run	August 11, 2026 at 20:45
estimated_db_size	3823.77 MiB
database_engine	mysql
database_version	11.4.10

Supervisor diagnostics

config_entry-hassio-3d8ee483a7d617d59ce709d815b0f501.json

Additional information

No response

[agners]

AI says:

Two plausible sources for cifs handing back ENOMEM there:

• Server-side: cifs maps STATUS_NO_MEMORY from the SMB server to -ENOMEM. A NAS low on buffers under a sustained multi-GB write would do exactly this.
• Host-side: kernel page/allocation pressure in the cifs writeback path. Odroid-N2 (4 GB) with a ~3.8 GB MariaDB recorder DB is a plausible setup for that, and "reboot fixes it for a couple of weeks" fits memory fragmentation much better than it fits an application bug.

Since you state that Home Assistant host machine reboot resolves the issue, it appears more likely 2 then?

Maybe check the memory usage on HA side (e.g. using the System monitor integration). If something continuously uses more memory, I'd try to isolate that. But from Supervisor side not much we can do, if there is not enough memory...

[estevez-dev]

AI says:

Two plausible sources for cifs handing back ENOMEM there:

• Server-side: cifs maps STATUS_NO_MEMORY from the SMB server to -ENOMEM. A NAS low on buffers under a sustained multi-GB write would do exactly this.
• Host-side: kernel page/allocation pressure in the cifs writeback path. Odroid-N2 (4 GB) with a ~3.8 GB MariaDB recorder DB is a plausible setup for that, and "reboot fixes it for a couple of weeks" fits memory fragmentation much better than it fits an application bug.

Since you state that Home Assistant host machine reboot resolves the issue, it appears more likely 2 then?

Maybe check the memory usage on HA side (e.g. using the System monitor integration). If something continuously uses more memory, I'd try to isolate that. But from Supervisor side not much we can do, if there is not enough memory...

Thanks for the quick reply; I'll monitor host memory usage then. Maybe it is time to retire my Home Assistant Blue ))