S3 Compatible Storage - The stream does not support concurrent IO read or write operations

Im trying to setup a Backup Job with a S3 compatible Storage, the connection is working fine but the upload fails with the following error:

Other posts with the same error had no solution, but it seems to be a S3 specific issue.
Duplicati Version is 2.0.6.3.

Any ideas?

  1. Febr. 2022 11:30: Failed while executing “Backup” with id: 6
    System.AggregateException: One or more errors occurred. —> System.AggregateException: The stream does not support concurrent IO read or write operations. —> System.NotSupportedException: The stream does not support concurrent IO read or write operations.
    at CoCoL.AutomationExtensions.d__101.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Duplicati.Library.Main.Operation.BackupHandler.<FlushBackend>d__19.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Duplicati.Library.Main.Operation.BackupHandler.<RunAsync>d__20.MoveNext() --- End of inner exception stack trace --- at Duplicati.Library.Main.Operation.BackupHandler.<RunAsync>d__20.MoveNext() --- End of inner exception stack trace --- at CoCoL.ChannelExtensions.WaitForTaskOrThrow(Task task) at Duplicati.Library.Main.Controller.<>c__DisplayClass14_0.<Backup>b__0(BackupResults result) at Duplicati.Library.Main.Controller.RunAction[T](T result, String[]& paths, IFilter& filter, Action1 method)
    at Duplicati.Library.Main.Controller.Backup(String[] inputsources, IFilter filter)
    at Duplicati.Server.Runner.Run(IRunnerData data, Boolean fromQueue)

I wonder if setting this might help:

--asynchronous-concurrent-upload-limit=1

What kind of S3 back end is this?

hi,
I’m new to duplicati.
same error here on windows 10 pro Duplicati - 2.0.6.3_beta_2021-06-17

--asynchronous-concurrent-upload-limit=1

didn’t help
I’m using S3 compatible (CEPH)

Looking at network tab in web developper of firefox shows only GET, no PUT if it can help
any idea?

Thank you
Gérald
log file generated :
gg.zip (15.1 KB)

testing few configs from other posts of this forum solved the problem :
s3-ext-signatureversion had to be set to 2 instead of 4…