Connect to S3 into Synology hyperbackup or cloud sync

[garanda21]

First, thank you for the great work on this project.

I’ve successfully deployed the Filen CLI with the S3 server using Docker, and it runs correctly.

However, I’m trying to connect it to my Synology NAS, and the connection consistently fails. The Synology S3 setup screen requires the following parameters (see attached image):

I've tried different ways, but no success.

Any suggestions?

[GiamBoscaro]

Hello. I have a similar problem! I can actually connect to filen.io server but it fails at the last step of the configuration wizard.
If you want to try, there are the settings you need to use in Hyperbackup:

• Server address: your S3 address
• Signature version: v4
• Access key: the one you have setup in the cli
• Secret key: the one you have setup in the cli
• Request style: path
• Bucket name: you can create a folder in Filen and it will be listed here as a bucket
• Directory: choose a name, default NAS_1

You will see that it works and can even create the NAS_1.hbk folder in Filen.io but the it will fail. The errors is this:

[err] transfer_s3.cpp:355 ETag is empty

convert response [{"ETag":"","RequestId":null,"success":true}] to finfo failed

I am now blocked here. Looks like Filen.io is returning an empty ETag and Hyberbackup sees this as a failure.

I even tried to ask ChatGPT and this was the answer

Until Filen implements real ETag hashing, HyperBackup cannot work with it — regardless of proxy configuration.

[GiamBoscaro]

Reply from filen.io support:

Hello,

Thanks for the detailed report.

From the error message, it seems like Synology Hyperbackup is expecting a valid ETag response after uploading, which our current S3-compatible server might not yet fully implement in the required way.

If you've followed the guide correctly and everything else works until that point, then yes—this could be a current compatibility limitation between Hyperbackup and our filen-s3 implementation.

We’ll take note of this behavior and investigate further, but in the meantime, it might not be fully compatible with Hyperbackup. If we find a workaround or patch, we’ll let you know!

Best regards,
Filen Support

[jutuiz]

I have probably the same issue.

The S3 server (in case a VM W11 with Filen Windows client) is reacheable from other devices.
But in Synology the Hyperbackup interface refuses to populate the "Bucket-name" field.

Edit: also Synology cloud sync (that seems to be less strict) still has the same issue. There it takes a time to load, and it gives:

List of buckets is not possible.