About open file (descriptor) limits on Home Assistant OS

[agners]

You likely got linked here because you see Too many open files or No file descriptors available errors in the log. A bit of background why this errors suddenly appear, and what you can do about them.

If you are a user, please wait until the respective issue has been resolved. You may downgrade to HAOS 15.2 (or whichever OS version did work for you) until the issue is resolved (use ha os update --version 15.2).

If you are a developer, here is some more details on how things came about.

First off, these two messages are the same OS error with the number 24, Too many open files is the string used on glibc based systems (often add-ons), No file descriptors available you will see on musl based systems (Home Assistant Core, Supervisor or add-ons as well).

The message essentially means that the application hit its limits of maximum open files allowed by the operating system (Linux). This is enforced on a kernel level for each process. Each process has two limits: A soft limit and a hard limit. The error appears as soon as the soft limit is reached.

Recently there have been changes in Docker, and with that Home Assistant OS, what this default soft limit exactly is set at. Initially it was set to 1048576, before it got raised in HAOS 10 (which caused issues for some add-ons, see #2438) and Docker 23 to 1073741816 (due to the configuration option infinity in the containerd service file, which raises it to the maximum the Linux kernel supports), and finally in HAOS 16, with Docker 28.3.0 and containerd 2.0, the new default is 1024 (which again caused issues for some add-ons, e.g. Frigate, see #4110 and Home Assistant Core itself see #4164).

This new value is inherited by containerd 2.0, which HAOS is using. There has been some quite deep investigation into how the limits changed over time in the containerd repository, notable containerd/containerd#7566 (comment). The main change was to remove any explicit limit with containerd/containerd#8924, which essentially makes every container to start as if the application would run without containerization, just on a vanilla Linux shell. And for typical shells the soft limit has always been 1024, with variable hard limits but typically it is set at 524288.

If the application in question is unlikely to have that many files open at the same time, there might be a bug in your application (e.g. by a resource leak, where a reference to open files got kept somewhere, causing the system to have more and more files open). In this case any higher limit simply delays the resource exhausted. Obviously in this case the resource leak should be addressed.

For application simply need more file descriptor than 1024 it should raise the soft limits on it's own. This is also the official advice from the systemd blog in their File Descriptor Limit post. It seems the runtime of some programming languages (Go) do that on their own. For Python you can use the resources package. It is also possible to simply raise the soft limit in shell (e.g. in your run script of the s6-overlay, by using ulimit -Sn "524288", technically the hard limit can be different depending on environment, but 524288 is a rather safe value at this point in time).

[jymbob]

If you are a user, please wait until the respective issue has been resolved.

Given #4164 has been marked as resolved in what's basically akin to a "not our problem" philosophy, what are end users supposed to make of this?

I fully appreciate the argument that poorly written integrations leaving files open is a problem for the maintainers of those integrations, but the end result is that a change in HAOS means Home Assistant Core is getting taking down for a number of users in a manner that's not well explained, and that's a definite regression.

At a bare minimum, home assistant's responsibility is to alert the user to the issue so they can know where to start looking for fixes.

[sairon]

Given #4164 has been marked as resolved in what's basically akin to a "not our problem" philosophy, what are end users supposed to make of this?

Sorry, it's not the way I wanted to communicate it. The issue was locked because the original cause of the problem was found and addressed (to some extent). There's nothing else to be done on OS side, as the limit is now handled by HA Core (since home-assistant/core#148806 - even if the OS limits were higher, Core would them to 2048).

Snowballing issue with tons of "me too" comments is never helpful, that's why every case should be investigated individually, either in the Core issue tracker, or with the help of the community on Discord or Community Forums. There are steps in the issue you linked that can be used to identify the source of the problem, although they are quite technical - we could think of how we it can be simplified.

Last not least, as I already stated elsewhere, the problem of poorly written integrations may have shined a bad light on Home Assistant's stability in the past as well - what manifests as breakage in 1 hour with current limits becomes a breakage in 10 days with the old ones. By then users were pretty sure it's Home Assistant who's to blame, now we've brought the real issue into the light.

[zSprawl]

I feel stuck as well. I can't upgrade because of the issue but I can't identify what integration is causing it without significant effort of turning a few integrations on, and waiting to see if something happens, over the course of weeks.

[thesebastianf]

There is an issue Open for the influx addon.
I think for influx this might Just be Not Something uncommon having many files Open if you also have many entities.

[thomasheiser85]

i am also stuck using https://github.com/Jays-Home-Assistant-Add-ons/j-addon-influxdb2

the addon is no longer starting. because of to many open files

[agners]

Home Assistant 2025.10.0 and later gained a sensor in the System Monitor integration. Enable the integration, then select Settings > Devices & services > System Monitor > Select the cog wheel and select python3 to monitor.

Then select the System Monitor integration, in the Diagnostic card select "xy disabled entities" to show all disabled entities. Find the "Open file descriptors python3" entity and select it. Select the cog wheel on the top right and toggle the "Enabled" option to enable the entity, select "Update".

The entity will have the count of open file descriptors of Home Assistant Core. The count should stay under 2048. If you experience problems like Home Assistant not reachable and similar issues, monitoring the process count can be helpful to see how the open file descriptor count changes over time.

Note: The entity technically shows a sum of open file descriptors for all processes named python3 inside the Home Assistant Core container. This is in a typical Home Assistant OS installation just a single process.

[Mariusthvdb]

I don't have it in HAOS either. pythor3 is added, but there is not that hidden sensor. Should it be there in HAOS?

yes, after setting the cogwheel, see the instructions above

[emufan]

yes, after setting the cogwheel, see the instructions above

I read the instructions. Did you read my post? I added phyton3 via cogtwheel. And there is no sensor enabled, nor a hidden sensor afterwards, which can be enabled. Same as zSprawl is reporting and I written in community

On what is your "yes" based on? You "read the instructions" everywhere is not very helpful here.

[Mariusthvdb]

On what is your "yes" based on?

your yes/no question:

Should it be there in HAOS?

and my HAOS available entities.

You "read the instructions" everywhere

these instructions got me there #4166 (comment)
after I read them and followed what they instructed

[zSprawl]

I'm still using 15.2 of the OS because when I update to 16.x, it all goes it hell in a hand basket.

Is this sensor perhaps not available in 15.2?

[jymbob]

I didn't see the sensor until a recent update. Not sure exactly which one it was, but it's now showing up and this, plus profiler.dump_sockets helped me identify the troublesome integration for me (in my case it was the LIFX integration failing to close sockets in some error cases relating to an IP clash, which I've reported)

[thesebastianf]

this PR home-assistant/supervisor#6206 mentions influx and that will give parameters to make settings.
I still have the issue only with influx addon and look for a way to set the limit higher for influx. There is yet no option in the addon configuraton

[sairon]

It's actually not in the user add-on configuration (aka options) but it needs to be configured by the add-on developer in the add-ons config.yaml: https://developers.home-assistant.io/docs/add-ons/configuration#optional-configuration-options

If you're using the Community add-on, I've opened a PR: hassio-addons/addon-influxdb#390

[Mariusthvdb]

apparently not resolved at all, and since the other issue has been locked, Ill add this here.

right... so after updating to HA 2025.11.x I encountered this issue for the first time.
but, it might also have been after also updating to OS 16.3

there isnt a lot to go on other than just before the first occurrences that finally took my system down because out of resources... there is a mention of Battery notes integration

2025-11-11 17:49:13.682 ERROR (SyncWorker_16) [homeassistant.util.file] Saving file failed: /config/.storage/battery_notes.storage
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/util/file.py", line 56, in write_utf8_file
  File "/usr/local/lib/python3.13/tempfile.py", line 583, in NamedTemporaryFile
  File "/usr/local/lib/python3.13/tempfile.py", line 580, in opener
  File "/usr/local/lib/python3.13/tempfile.py", line 257, in _mkstemp_inner
OSError: [Errno 24] No file descriptors available: '/config/.storage/tmplb2alhmm'
2025-11-11 17:49:13.690 ERROR (MainThread) [homeassistant.helpers.storage] Error writing config for battery_notes.storage: [Errno 24] No file descriptors available: '/config/.storage/tmplb2alhmm'
2025-11-11 17:50:10.044 WARNING (MainThread) [homeassistant.components.hassio.coordinator] Could not fetch info for a0d7b954_nut: Error occurred connecting to supervisor
2025-11-11 17:50:10.047 WARNING (MainThread) [homeassistant.components.hassio.coordinator] Could not fetch info for a0d7b954_ssh: Error occurred connecting to supervisor
2025-11-11 17:50:10.050 WARNING (MainThread) [homeassistant.components.hassio.coordinator] Could not fetch info for core_matter_server: Error occurred connecting to supervisor
2025-11-11 17:50:10.052 WARNING (MainThread) [homeassistant.components.hassio.coordinator] Could not fetch info for 8bce8ef4_dbstats: Error occurred connecting to supervisor
2025-11-11 17:50:26.346 ERROR (MainThread) [homeassistant.components.spotify.coordinator] Error requesting spotify data: Cannot connect to host api.spotify.com:443 ssl:default [Could not contact DNS servers]
2025-11-11 17:50:32.382 INFO (MainThread) [backoff] Backing off fetch_events(...) for 0.4s (aiohttp.client_exceptions.ClientConnectorError: Cannot connect to host ha101-1.overkiz.com:443 ssl:default [No file descriptors available])
2025-11-11 17:50:32.385 ERROR (MainThread) [homeassistant.components.overkiz] Error fetching device events data: Failed to connect.
2025-11-11 17:50:32.950 ERROR (MainThread) [homeassistant.components.systemmonitor.coordinator] Unexpected error fetching System Monitor update coordinator data
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 403, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/systemmonitor/coordinator.py", line 142, in _async_update_data
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 59, in run
  File "/usr/src/homeassistant/homeassistant/components/systemmonitor/coordinator.py", line 188, in update_data
  File "/usr/local/lib/python3.13/site-packages/psutil/__init__.py", line 2051, in swap_memory
  File "/usr/local/lib/python3.13/site-packages/psutil/_pslinux.py", line 477, in swap_memory
  File "/usr/local/lib/python3.13/site-packages/psutil/_common.py", line 764, in open_binary
  File "/usr/src/homeassistant/homeassistant/util/loop.py", line 201, in protected_loop_func
OSError: [Errno 24] No file descriptors available: '/proc/meminfo'
2025-11-11 17:50:33.377 ERROR (MainThread) [homeassistant.components.ping.coordinator] Unexpected error fetching Ping 192.168.1.148 data
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/site-packages/icmplib/sockets.py", line 88, in __init__
  File "/usr/local/lib/python3.13/site-packages/icmplib/sockets.py", line 466, in _create_socket
  File "/usr/local/lib/python3.13/socket.py", line 233, in __init__
OSError: [Errno 24] No file descriptors available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 403, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/ping/coordinator.py", line 55, in _async_update_data
  File "/usr/src/homeassistant/homeassistant/components/ping/helpers.py", line 55, in async_update
  File "/usr/local/lib/python3.13/site-packages/icmplib/ping.py", line 274, in async_ping
  File "/usr/local/lib/python3.13/site-packages/icmplib/sockets.py", line 102, in __init__
icmplib.exceptions.ICMPSocketError: [Errno 24] No file descriptors available
2025-11-11 17:50:35.056 ERROR (MainThread) [homeassistant.components.waqi] Error requesting Houtlaan, Nijmegen data: Cannot connect to host api.waqi.info:443 ssl:default [No file descriptors available]
2025-11-11 17:50:35.146 ERROR (MainThread) [homeassistant.components.waqi] Error requesting Zevenbergen, Brabant data: Cannot connect to host api.waqi.info:443 ssl:default [No file descriptors available]
2025-11-11 17:50:35.177 ERROR (MainThread) [homeassistant.components.waqi] Error requesting Kallo (liefkenshoektunnel), Belgium data: Cannot connect to host api.waqi.info:443 ssl:default [No file descriptors available]
2025-11-11 17:50:48.009 ERROR (MainThread) [homeassistant.components.systemmonitor.coordinator] Unexpected error fetching System Monitor update coordinator data
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 403, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/systemmonitor/coordinator.py", line 142, in _async_update_data
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 59, in run
  File "/usr/src/homeassistant/homeassistant/components/systemmonitor/coordinator.py", line 188, in update_data
  File "/usr/local/lib/python3.13/site-packages/psutil/__init__.py", line 2051, in swap_memory
  File "/usr/local/lib/python3.13/site-packages/psutil/_pslinux.py", line 477, in swap_memory
  File "/usr/local/lib/python3.13/site-packages/psutil/_common.py", line 764, in open_binary
  File "/usr/src/homeassistant/homeassistant/util/loop.py", line 201, in protected_loop_func
OSError: [Errno 24] No file descriptors available: '/proc/meminfo'

not sure if this is the actual cause, hope anyone of the devs here can shed some light.

the rest of the log consists of

2025-11-11 17:51:00.940 ERROR (MainThread) [homeassistant] Fatal error '[Errno 24] No file descriptors available' raised in event loop, shutting it down
2025-11-11 17:51:00.941 ERROR (MainThread) [asyncio] Unhandled error in exception handler
context: {'message': 'socket.accept() out of system resource', 'exception': OSError(24, 'No file descriptors available'), 'socket': <asyncio.TransportSocket fd=14, family=2, type=1, proto=6, laddr=('0.0.0.0', 42938)>}
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/asyncio/selector_events.py", line 178, in _accept_connection
    conn, addr = sock.accept()
                 ~~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/socket.py", line 295, in accept
OSError: [Errno 24] No file descriptors available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.13/asyncio/base_events.py", line 1933, in call_exception_handler
    self._exception_handler(self, context)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/runner.py", line 251, in _async_loop_exception_handler
    loop.close()
    ~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/asyncio/unix_events.py", line 70, in close
  File "/usr/local/lib/python3.13/asyncio/selector_events.py", line 101, in close
    raise RuntimeError("Cannot close a running event loop")
RuntimeError: Cannot close a running event loop

I posted in 2025.11 topic here

of course, this is a bad thing mo matter what. because, how to get out of this and not have to ssh in and command_line to finally restart

I was lucky enough to have installed the custom log file creator by Petro, otherwise I would have been way more out of luck, because of the demise of the log file in 2025.11

Couldnt some system tool be available to guard the system from running out of resources and finally halting?

would have been way more user friendly if this would be handled inside the OS, or supervisor, or ...

let me know if you need more to analyse what happened, I'd be glad to get this sorted
thanks

PS, if you can, let me know if the custom integration that creates the .log file could be involved at all.
just trying to rule out anything new that caused this

2025.11
OS 16.3
custom integration a File logger

[Mariusthvdb]

and more explicit than this cant it be, happened again last night
cant even ssh in to do ha core restart this time....

well, not at hassio.local, I can by connection to the ip address.. might that be a lead?

RuntimeError: Executor shutdown has been called
2025-11-13 01:12:49.462 CRITICAL (SyncWorker_14) [concurrent.futures] Exception in worker
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/local/lib/python3.13/socket.py", line 977, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
               ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
socket.gaierror: [Errno -5] Name has no usable address

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 93, in _worker
    work_item.run()
    ~~~~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 61, in run
    self.future.set_exception(exc)
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/usr/local/lib/python3.13/concurrent/futures/_base.py", line 552, in set_exception
    def set_exception(self, exception):
    
SystemExit

and back,

right after restart... which means the

from yesterday was already rather high..? does that indicate a leak of sorts

nothing in Cpu or memory indicate that really

[Mariusthvdb]

no real obvious start, other maybe than a DNS failure, after which the same tsunami from before occurs:

2025-11-12 23:43:52.201 INFO (MainThread) [backoff] Backing off fetch_events(...) for 1.0s (aiohttp.client_exceptions.ClientConnectorDNSError: Cannot connect to host ha101-1.overkiz.com:443 ssl:default [Timeout while contacting DNS servers])
2025-11-13 01:11:03.235 ERROR (MainThread) [homeassistant.components.ping.coordinator] Unexpected error fetching Ping 192.168.1.254 data
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/site-packages/icmplib/sockets.py", line 88, in __init__
  File "/usr/local/lib/python3.13/site-packages/icmplib/sockets.py", line 466, in _create_socket
  File "/usr/local/lib/python3.13/socket.py", line 233, in __init__
OSError: [Errno 24] No file descriptors available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 403, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/ping/coordinator.py", line 55, in _async_update_data
  File "/usr/src/homeassistant/homeassistant/components/ping/helpers.py", line 55, in async_update
  File "/usr/local/lib/python3.13/site-packages/icmplib/ping.py", line 274, in async_ping
  File "/usr/local/lib/python3.13/site-packages/icmplib/sockets.py", line 102, in __init__
icmplib.exceptions.ICMPSocketError: [Errno 24] No file descriptors available
2025-11-13 01:11:13.974 ERROR (MainThread) [homeassistant.components.systemmonitor.coordinator] Unexpected error fetching System Monitor update coordinator data
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 403, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/systemmonitor/coordinator.py", line 142, in _async_update_data
    _data = await self.hass.async_add_executor_job(self.update_data)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/src/homeassistant/homeassistant/components/systemmonitor/coordinator.py", line 188, in update_data
    swap = self._psutil.swap_memory()
  File "/usr/local/lib/python3.13/site-packages/psutil/__init__.py", line 2051, in swap_memory
    return _psplatform.swap_memory()
           ~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/site-packages/psutil/_pslinux.py", line 477, in swap_memory
    with open_binary(f"{get_procfs_path()}/meminfo") as f:
         ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/psutil/_common.py", line 764, in open_binary
    return open(fname, "rb", buffering=FILE_READ_BUFFER_SIZE)
  File "/usr/src/homeassistant/homeassistant/util/loop.py", line 201, in protected_loop_func
    return func(*args, **kwargs)
OSError: [Errno 24] No file descriptors available: '/proc/meminfo'
2025-11-13 01:12:42.549 ERROR (MainThread) [homeassistant] Error doing job: socket.accept() out of system resource (None)
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/asyncio/selector_events.py", line 178, in _accept_connection
    conn, addr = sock.accept()
                 ~~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/socket.py", line 295, in accept
OSError: [Errno 24] No file descriptors available
2025-11-13 01:12:42.551 ERROR (MainThread) [homeassistant] Fatal error '[Errno 24] No file descriptors available' raised in event loop, shutting it down
2025-11-13 01:12:42.552 ERROR (MainThread) [asyncio] Unhandled error in exception handler
context: {'message': 'socket.accept() out of system resource', 'exception': OSError(24, 'No file descriptors available'), 'socket': <asyncio.TransportSocket fd=12, family=2, type=1, proto=6, laddr=('0.0.0.0', 42938)>}
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/asyncio/selector_events.py", line 178, in _accept_connection
    conn, addr = sock.accept()
                 ~~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/socket.py", line 295, in accept
OSError: [Errno 24] No file descriptors available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.13/asyncio/base_events.py", line 1933, in call_exception_handler
    self._exception_handler(self, context)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/runner.py", line 251, in _async_loop_exception_handler
    loop.close()
    ~~~~~~~~~~^^
  File "/usr/local/lib/python3.13/asyncio/unix_events.py", line 70, in close
  File "/usr/local/lib/python3.13/asyncio/selector_events.py", line 101, in close
    raise RuntimeError("Cannot close a running event loop")
RuntimeError: Cannot close a running event loop

[sairon]

1519 opened FDs looks indeed quite suspicious, limit is 2048. Assuming they could be caused by network connections, you can use the profiler.dump_sockets action - for that enable the Profiler integration and once it starts to reach high value, use the developer tools to call the action and inspect the logs. If the high number of FDs correlates with the number of lines dumped to the log, the addresses there could give you a clue what integration is misbehaving.

[Mariusthvdb]

Ok thanks will try to get at profiler in time

I did see that my browser couldn’t connect to Hassio.local but was still able to get to /ipaddress:port

could dns be causing this kind of trouble?

also, I’ve enabled an automation to restart when above 2000, but should I lower that, as you’re saying 1500+ is already high?

[Mariusthvdb]

can we dump that into a log file of sorts?

action: profiler.dump_sockets
target: /config/profiler_dump_sockets.txt

obviously doesnt work, maybe need some other syntax

I mean, having that in the harder to reach home-assistant.log these days is not very obvious either