Issue with backing up from Network share

Hi there,

i´m trying Duplicati for the first time and it seems nice so far, but im running into issues when i´m trying to backup from a network share.
So far the Setup looks like this:
Duplicati running as service on Windows Server2012R2-DC, is set to backup the data from the local D:-Drive and i also added the path \\\backup\ which is a QNAP-Nas share which contains some Linux-application .zip backup files.
So far the backups from the local D:-Drive are working as intended, but there is a problem with the share.
I´m getting 2021-02-24 08:29:52 +01 - [Warning-Duplicati.Library.Main.Operation.Backup.MetadataGenerator.Metadata-MetadataProcessFailed]: Failed to process metadata for "\\\backup errors for each file on the share, which to me is showing that Duplicati is able to read the contents from the share.
On the Qnap side i allowed for access from the 2012R2 Serveraccount, and i can log into the share from the server without any credentials, R/W access, no problems.
So… what can i do to make it work?

I have to correct myself, i´m getting these errors just for a couple of files from the share, not all of them, which makes it even weirder. The files that don´t throw the errors are not getting backed up either.
The shown source size of the backupjob is what i would expect it to be, so clearly Duplicati can see all the files and it´s sizes, but somehow is not able to back them up.

Seems like it was some weird file system ACL issue on the QNAP side.
Had to reset and reapply the folder/file permissions, now it seems to backup the files.

Thanks for following up… glad you were able to solve your issue!

I have the same problem as @x86 with the NAS on a fritzbox 7560. Fritzbox 7560 is a box with USB ports to attach hard drives, that I can then mount in Win 7.
The problem started when the fritzbox updated its OS to FRITZ!OS 07.27

I believe the error message is related to the SMB version of the SMB server in the fritzbox, because I also got problems with a Win XP machine not being able to access the NAS. I ticked in the box settings:
‘Activate support for SMBv1’ and the XP machine could access the NAS.

Duplicati starts as a task with elevated rights when I log on to Win 7, so I think Duplicati has access to the network share, at least there were no warnings prior to the box OS update. Yet when I back up the network share Z:, I get many instances of
2021-06-12 23:26:42 +02 - [Warning-Duplicati.Library.Main.Operation.Backup.MetadataGenerator.Metadata-MetadataProcessFailed]: Failed to process metadata for “Z:\lisezmoi.txt”, storing empty metadata.

I took the following measures: disconnect the network share, reconnect it.

Your thoughts on this topic?


Duplicati -
Windows 7 Pro version 6.1 (build 7601)
FRITZ!OS: 07.27, SMBv1 active

Hi there,

as i stated, in my case it was an ACL issue. My problem originated in the underlaying Linux filesystem ACLs.
My Linux server backed up to the QNAP-network share with its own ACLs and therefore Duplicati couldn´t access it from the Windows-Server. I resolved that issue with a cronjob that sets the ACLs to what i need them to be to back up the files before Duplicati runs.
Are all the files you get this problem with last saved from the XP-Machine?

Could you ask the provider of the update for clues? I did a bit of web searching, but didn’t find anything other than I think they added new SMB versions recently. Windows 7 can do SMB 2.1 I think. XP is 1.0 which is deprecated (or removed) in newer Windows because of security risks from running SMB 1.0.

Is that just an example, or is it that one file? If many files, is it pretty much every file, or is there a pattern?
Metadata would normally be things like timestamps (Windows has Created and Modified, with Modified a more common and essential one), and maybe security attributes such as the NTFS access control lists.

Can you Explorer right-click Warning file to use Properties to see if General and Security tabs work?
Duplicati will need at least Modified, but to ignore the rest (if you don’t care) you might try skip-metadata:

--skip-metadata = false
Use this option to disable the storage of metadata, such as file timestamps. Disabling metadata storage will speed up the backup and restore operations, but does not affect file size much.

Even better would be if AVM or @x86 (thanks!) can help you find out how to read file metadata normally.

I also googled Fritz!box in conjunction with Duplicati and found out that most people have problem backing up on the Fritz!box NAS, not from the Fritz!box NAS as I do.

Each and every file residing on the Fritz!box NAS I want to back up with Duplicati, gives rise to a warning.

I think @x86 and you are right about the ACL. Please see the snapshot of the Properties windows of a NAS file: there is no Security tab.

Yet the NAS file has a Date Modified attribute. I don’t know if files on network shares are supposed to have a Security tab. I checked a file in the GMX Mediacenter, mounted in Win 7: also no Security tab.

AVM GmbH is not very reactive… I’ll try them if everything else fails.

Your advice to skip-metadata works brilliantly though: no more warnings ! so I might stay here and call it a solved problem.

Thank you guys und Mädels !

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