Backup & Restore: "[Warning] Can't chown '/USB2/<filename>' [Operation not permitted(-1)]"

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Jarod24
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Backup & Restore: "[Warning] Can't chown '/USB2/<filename>' [Operation not permitted(-1)]"

Post by Jarod24 »

tldr: Backup & Restore: "[Warning] Can't chown '/USB2/<filename>' [Operation not permitted(-1)]" when target is using exFat

ADM Version: 4.2.RC81
Model: AS6704T

Steps to reproduce:
Backup & Restore -> External Backup -> Run a backup named 'AllFolders'
'AllFolders' = Transfer mode: Your NAS -> External device
Basically: a bunch of folders copied from my volume1 (Btrfs) to an external USB drive.

After the backup is finished I receive 54 463 (yes; fifty four thousand) warnings like this:
[Warning] Can't chown '/USB2/<filename>' [Operation not permitted(-1)]
The reason: /USB2 device uses exFat
exFAT does not support ACL so no surprise there.

The warning is technically not wrong; but outputting one for each file copied should not be necessary.
The file(s) data have been successfully copied over to the target drive. The only thing that is not transferred is the file(s) ACL info
If any other types of warnings/errors were to be occur on such a job then the user would most likely not see them since they would dissapear in a sea of these warnings.

Suggested solution:
If the service detects that the target drive is using exFat then either:
A) these warning should not be outputted at all as exFat does not support ACL and therefore this is not a bug.
B) all warnings of this type could be summarized into a single line explaining the issue; 'could not set chown for 54 463 file(s) since the target filesystem is exFat'

Maybe add a checkbox when creating a backup job to explicitly ignore such ACL errors.

For some users, copying file ACL's might be a requirement and informing them that a target drive uses exFat and do not support this when starting a backup job might be another alternative.
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Nazar78
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Re: Backup & Restore: "[Warning] Can't chown '/USB2/<filename>' [Operation not permitted(-1)]"

Post by Nazar78 »

This is perfectly normal similar to any other CLIs. It would take additional resources to keep track of the errors and what to do with them thus slight impact to the operation. You can always easily write your own backups by redirecting the STDERR to 2>/dev/null or manipulate them as you wish if you're bordered about warnings.
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tortor
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Re: Backup & Restore: "[Warning] Can't chown '/USB2/<filename>' [Operation not permitted(-1)]"

Post by tortor »

Hi Asustor team,

I have the same issue which is kind of annoying since you cannot quickly tell if it is only permissions that failed or something else. Is there a chance that you fix the error handling here?

BR,

Lars
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