Hi everyone,
I’m using the official Duplicati 2.4.0.0 SPK on Synology DSM 7 and looking for guidance on source-file permissions.
My applications run in Docker on a separate machine, with their persistent data stored on Synology Volumes over NFS. Duplicati runs natively on the NAS (manually installed spk - not docker based) - and reads those files locally.
I’ve granted the duplicati system user read-only access to the shared folder. Most files back up successfully, but some are skipped:
- Files owned by root or application users, with Unix permissions such as
640. - Files with explicit Synology ACLs that don’t grant access to
duplicati.
Here’s a short log sample:
Version: 2.4.0.0
ParsedResult: Warning
WarningsActualLength: 130
ErrorsActualLength: 0
[Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PermissionDenied]:
Excluding path due to permission denied: /volumeX/shared/stack/app/data/app.db
[Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PermissionDenied]:
Excluding path due to permission denied: /volumeX/shared/stack/app/config/notifications/service.yaml
The upload and remote verification succeed, but these source files are explicitly excluded. For two affected files, I confirmed that duplicati cannot read them while root can. I haven’t modified the package’s privileges.
Hyper Backup didn’t produce similar warnings; I suspect it have privileged access that the native Duplicati package lacks.
I found this discussion about source-file permissions, where matching the Docker container’s UID/GID to the source owner resolved the issue, and this older capabilities report. My source files belong to several different application users, though, and Duplicati runs as the native DSM package.
What’s the recommended, supported approach for the current native Synology package? Is privileged read access available—for example through a helper or CAP_DAC_READ_SEARCH—in a way that survives package updates?
I’d prefer to avoid changing application-file permissions, installing Docker on the NAS, or maintaining a custom root-service setup.
Thanks for any guidance!