Synology NFS shares unavailable in VBR v12

[SLienenlueke]

Hello there,

we are facing some troubles with our backup repos after upgrading or installing (to) VBR v12. NFS shares v4.1.
The error message is "Cannot find compatible gateway server for repository ..."
The support case ID is 05944861.
All repos are on Synology NAS.
Changing the repo's gateway server from automatic to a dedicated server did not help.
We re-clicked the repo's and proxy's configuration, but that did not help.
We implemented a registry key to define the NFS-Version without success.
We de- and reinstalled the Mount, Installer and Transportation Service without any changes.
Downgrading the NFS-version to v3 fixes the problem but that's not really a way that we see as a solution.
Is anybody else facing this issue?

Kind regards,
Simon

[sgobrien]

Seeing opposite issue since v12 upgrade and Synology NAS as repo (using NFS v3)
Switching to v4.1 seemed to help. But seeing some odd issue with that as well.

Getting errors like:
Boost::thread_resource_error. resource temporarily unavailable
NFS server is unavailable, or specified share cannot be accessed.

Mounting NFS share in OS works fine
Support case ID: 05985392

[BastianR82]

Hi!

Today after Synology Update to DSM 7.1.1-42962 Update 5 NFS3 stopped working with "Unable to allocate processing resources. Error: Cannot find compatible gateway server for repository Synology NFS Storage".
Could not get it to work again, only after setting NFS in the Synology to 4.1. Reconfigured NFS shares in veeam, backups working normally again. Could not find any NFS changes in the Synology changelogs.

Greets,
Bastian

[sgobrien]

Checked Synology DSM version, I'm still running DSM 7.1.1-42962 Update 4.
I have switched over to NFS4.1, but getting cannot enumerate folder warnings now on several folders.

[SLienenlueke]

This is the reply that i got from the support team:
Windows-based gateway servers cannot be used for NFS shares with krb5i and krb5p support.


Thank you for the updates.
We have involved our senior engineers and we have discovered the following:
[21.04.2023 09:56:08.224] < 16284> nfs | ERR |[NFS41] nfs41_rpc_clnt_create: failed to create AUTHGSS_KRB5P
[21.04.2023 09:56:08.224] < 16284> nfs | ERR |[NFS41] nfs41_rpc_clnt_create: failed to establish security context with SYNOLOGY-NAS

We have detected that the KRB5P authentication is failing and it looks to be the reason of the connection failure ti the NFS 4.1 share.
According to the UserGuide:

Windows-based gateway servers cannot be used for NFS shares with krb5i and krb5p support.

This limitation was introduced in VBR v12, which explains why the jobs started failing after the VBR upgrade.
In this case, the supported way of using the NFS share v.4.1 is to deploy a Linux Gateway server to be able to work with krb5i and krb5p.

[MoritzG-Seidemann]

@SLienenlueke Do you by any chance know where they found that log entry so I could take a look myself?
I have an NFS error where the gateway fails to access the NFS-share on our Synology NAS (Usually DS220j and DS223j).
If the issue occurred it seemed to be connected via NFS4.1 and when repopulating (without changing any settings) it reconnected without any issues (for now).
Upon repopulating one client chose NFS3 as the protocol, the other NFS4.1 for the repo. I havent compared the versions of DSM so far.
Both of our clients have fresh Veeam B/R v12 installs without upgrades from earlier versions (excluding v12 updates and patches).

[SLienenlueke]

Hello Moritz,

I'll try to find the correct log and let you know. Right now we are having troubles with various Synology NFS3 repos from different customers.
The VBR cannot connect to them although they are up and running. The error message says, that the VBR could not find a valid gateway server.
This happens from time to time, I started to create SMB repos for the same location to have more stability.