b__ 0 (Duplicati.Library.Main.BackupResults result) [0x0004b] in <9cab5b8f1b4f49ec980acae8e278968b>:0
at Duplicati.Library.Main.Controller.RunAction[T] (T result, System.String[]& paths, Duplicati.Library.Utility.IFilter& filter, System.Action`1[T] method) [0x0026f] in <9cab5b8f1b4f49ec980acae8e278968b>:0
at Duplicati.Library.Main.Controller.Backup (System.String[] inputsources, Duplicati.Library.Utility.IFilter filter) [0x00074] in <9cab5b8f1b4f49ec980acae8e278968b>:0
at Duplicati.Server.Runner.Run (Duplicati.Server.Runner+IRunnerData data, System.Boolean fromQueue) [0x00349] in <30a34d71126b48248d040dda634ddad9>:0 ```
````
---
### Author:  [@gpatel-fr](https://forum.duplicati.com/u/gpatel-fr)
#### Post date: [September 10, 2023, 5:07am UTC](https://forum.duplicati.com/t/backup-failed-could-not-find-file-help/16760/2 "2023-09-10T05:07:52Z")
> [@Randy](#):
>
> For context, I am using portainer
Well, that’s the first time I see the word. Computer are long, life is short. Help will be limited from my part.
> [@Randy](#):
>
> I can configure the backup and all “tests” for destination and source pass during backup configuration
That don’t prove much about anything. For most backends - I think the only exception is Ftp backends - the ‘test’ during backup is very limited, it’s basically a verification that a list call don’t return an error. There is no attempt at writing a file. Just verified: it’s the same for the file backend.
FTR a simple search of this forum returns the following post:
> [@Could not find file ""](https://forum.duplicati.com/t/could-not-find-file/14961):
>
> Hi, I have Duplicati running on my Fedora Core server in a docker container. Duplicati is set up to backup 2 local folders to my QNAP NAS. I tried mounting the QNAP via nfs and via cifs. This setup used to work, but I reinstalled the OS on my server and now does not anymore. The backup job starts and after a few seconds throws the error “Could not find file “””. When starting the backup job via Commandline I receive the following stack trace Backup started at 9/11/2022 8:35:55 PM Checking remo…
It’s the very same error message so there is hope of finding a solution by fiddling with the container configuration.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [September 10, 2023, 11:26am UTC](https://forum.duplicati.com/t/backup-failed-could-not-find-file-help/16760/3 "2023-09-10T11:26:24Z")
There are also manually run tests available such as [Duplicati.CommandLine.BackendTester.exe](https://duplicati.readthedocs.io/en/latest/07-other-command-line-utilities/#duplicaticommandlinebackendtesterexe):
> Before you start using a particular backend to use as a backup target, you can use the Backend Tester to get an indication of the integrity of that backend.
This one’s automatic, with some options. Give it a target URL, e.g. from [Export As Command-line](https://duplicati.readthedocs.io/en/latest/03-using-the-graphical-user-interface/#exporting-a-backup-job-configuration).
[Using Duplicati from the Command Line](https://duplicati.readthedocs.io/en/latest/04-using-duplicati-from-the-command-line/)
[Using the Command line tools from within the Graphical User Interface](https://duplicati.readthedocs.io/en/latest/03-using-the-graphical-user-interface/#using-the-command-line-tools-from-within-the-graphical-user-interface)
[Duplicati.CommandLine.BackendTool.exe](https://duplicati.readthedocs.io/en/latest/07-other-command-line-utilities/#duplicaticommandlinebackendtoolexe) is a manual tool you could try if you don’t like automatic.
I don’t use Portainer or Docker (whose Docker image is this anyway?), so can’t solve configuration.
> [@Randy](#):
>
> I have mapped my drives correctly
Different vendors’ images do the mapping differently, so I don’t know what this means for your case.
For testing purposes, you could possibly even rig up an unmapped in-container area for tiny backup.
That should remove the question of whether there’s a mapping problem behind whatever’s going on.
Presumably you have the Destination as `Local folder or drive`, and GUI-navigated to the folder.
That would probably avoid the excess or wrong slashes that people sometimes type for destinations.
> [@Randy](#):
>
> verified that the container can see every directory.
I’m not a Docker expert, but isn’t it actually that the process of interest (whatever UID it is) can see it?
There are still permissions that vary inside a container. About → System info shows what Duplicati is.