Backup to Cloud Fails to Home Assistant Cloud

[stu1811]

The problem

I have my system setup to backup to the HA Cloud and a local CIFS share. The CIFS share is unencrypted and seems to work fine. I get an error when backing up the cloud. The logs indicate a problem encrypting the data before uploading to the cloud.

What version of Home Assistant Core has the issue?

core-2025.3.4

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

Backup

Link to integration documentation on our website

No response

Diagnostics information

Every night my automated backup fails. Snippets below are from the core logs.

Logger: homeassistant.components.backup
Source: components/backup/manager.py:579
integration: Backup (documentation, issues)
First occurred: April 1, 2025 at 8:16:42 AM (4 occurrences)
Last logged: 5:23:52 AM

Upload failed for cloud.cloud: Indicated size 1489090560 does not match actual size 1488437760
Upload failed for cloud.cloud: Indicated size 1407354880 does not match actual size 1406713344
Upload failed for cloud.cloud: Indicated size 1427425280 does not match actual size 1426779136
Upload failed for cloud.cloud: Indicated size 1422008320 does not match actual size 1421358592

Logger: root
Source: components/backup/util.py:441
First occurred: April 1, 2025 at 8:16:42 AM (4 occurrences)
Last logged: 5:23:52 AM

Uncaught thread exception
Traceback (most recent call last):
  File "/usr/local/lib/python3.13/threading.py", line 1041, in _bootstrap_inner
    self.run()
    ~~~~~~~~^^
  File "/usr/local/lib/python3.13/threading.py", line 992, in run
    self._target(*self._args, **self._kwargs)
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/backup/util.py", line 393, in encrypt_backup
    _encrypt_backup(input_tar, output_tar, password, nonces)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/backup/util.py", line 441, in _encrypt_backup
    nonce=nonces[inner_tar_idx],
          ~~~~~~^^^^^^^^^^^^^^^
IndexError: list index out of range

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

No response

[home-assistant]

Hey there @home-assistant/cloud, mind taking a look at this issue as it has been labeled with an integration (cloud) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of cloud can trigger bot actions by commenting:

• @home-assistant close Closes the issue.
• @home-assistant rename Awesome new title Renames the issue.
• @home-assistant reopen Reopen the issue.
• @home-assistant unassign cloud Removes the current integration label and assignees on the issue, add the integration domain after the command.
• @home-assistant add-label needs-more-information Add a label (needs-more-information, problem in dependency, problem in custom component) to the issue.
• @home-assistant remove-label needs-more-information Remove a label (needs-more-information, problem in dependency, problem in custom component) on the issue.

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cloud documentation
cloud source
_{^{(message by IssueLinks)}}

[home-assistant]

Hey there @home-assistant/core, mind taking a look at this issue as it has been labeled with an integration (backup) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of backup can trigger bot actions by commenting:

• @home-assistant close Closes the issue.
• @home-assistant rename Awesome new title Renames the issue.
• @home-assistant reopen Reopen the issue.
• @home-assistant unassign backup Removes the current integration label and assignees on the issue, add the integration domain after the command.
• @home-assistant add-label needs-more-information Add a label (needs-more-information, problem in dependency, problem in custom component) to the issue.
• @home-assistant remove-label needs-more-information Remove a label (needs-more-information, problem in dependency, problem in custom component) on the issue.

_{^{(message by CodeOwnersMention)}}

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backup documentation
backup source
_{^{(message by IssueLinks)}}

[MartinHjelmare]

CC @emontnemery

[N3m3515]

got the same problem

[emontnemery]

@stu1811 Can you reproduce the problem?

[N3m3515]

@stu1811 Can you reproduce the problem?

Of course. It happens on every Backup.

[emontnemery]

@N3m3515 OK! Could you contact me on Discord, my username there is @emontnemery?

I think the problem might be that supervisor fails to create some part of the backup, either of one of the folders or of one of the add-ons.
It might be easiest to work that out in a Discord chat, but if you're not using Discord could you:

• Locate the most recent backup tar file
• List the contents of the tar file
• Extract backup.json from the tar file and attach it here

Also, please check if there's any relevant message in the supervisor log.

[N3m3515]

@N3m3515 OK! Could you contact me on Discord, my username there is @emontnemery?

I think the problem might be that supervisor fails to create some part of the backup, either of one of the folders or of one of the add-ons. It might be easiest to work that out in a Discord chat, but if you're not using Discord could you:

* Locate the most recent backup tar file

* List the contents of the tar file

* Extract `backup.json` from the tar file and attach it here

Also, please check if there's any relevant message in the supervisor log.

i have sent you a friend request on Discord

backup.json

i found this in the supervisor log:

[emontnemery]

Thanks a lot @N3m3515, the reason for failing to encrypt is that there are unexpected tar-files in the backup resulting from failing to complete back up of node-red and whisper.

We should handle this better in core by not blowing up, and also in supervisor by failing the backup.

And, of course, we should try to investigate why the add-ons can't be backed up.

[N3m3515]

What can i provide to aid with that?

[stu1811]

I have a similar error in my supervisor log
2025-05-08 05:22:41.717 ERROR (MainThread) [supervisor.addons.addon] Can't write tarfile <securetar._InnerSecureTarFile object at 0x7f677d6c33f0>: Error adding /data/addon_configs/core_zwave_js to tarfile: [Errno 2] No such file or directory: '/data/addon_configs/core_zwave_js' (FileNotFoundError) 2025-05-08 05:22:41.717 ERROR (MainThread) [supervisor.backups.backup] Can't create backup for core_zwave_js 2025-05-08 05:22:41.717 WARNING (MainThread) [supervisor.backups.backup] Can't save Add-on core_zwave_js: Can't create backup for core_zwave_js

[emontnemery]

As mentioned above, this issue revealed three separate issues:

• Core should not attempt to cipher unknown tar-files, fixed by: Don't encrypt or decrypt unknown files in backup archives #144495
• Supervisor should not fail backing up an add-on which has no data, fixed by: Handle non-existing addon config dir supervisor#5871
• Supervisor should mark back up as failed if an add-on can't be backed up: TODO