Can't backup to network share without credentials on Windows

[sirdeekay]

I do backups to a shared folder on my Synology NAS - this folder is unprotected meaning I can access it without a username and password (both read and write). This worked fine in Windows 8.1 and VEB 1.0.

Now with Windows 10 and VEB 1.1 I can no longer do so. When I configure the Backup and click the "Polulate" button it says: Failed to get disk free space
I can enter my admin account in the credentials field below to get it to work - but I should not have to.

Same is true for restoring/browsing backups - the Backup browser asks for User/Password despite me being able to access the files without a password through windows explorer for example.

Case # 00985863

[Dima P.]

Hello sirdeekay,

I do backups to a shared folder on my Synology NAS - this folder is unprotected meaning I can access it without a username and password (both read and write)

To clarify, the shared folder is accessible via regular windows browser? Can you copy/paste any file inside?

[sirdeekay]

Yes I can create new files and also delete them. Just tried it with a SMB browser on my phone to be extra sure I haven't saved any credentials.

[Dima P.]

Thanks for checking! And what happens if you leave the checkbox ‘This share requires access credentials’ unchecked? Are you able to finalize the configuration and complete the backup successfully?

[sirdeekay]

No, when I click Next it says: The specified server cannot perform the requested operation. Failed to create or open file.

[Dima P.]

sirdeekay,
Thanks. Unfortunately, I got nothing to add, so lets await for the investigation results: I’ve asked QA team to take a look at your case.

[Dima P.]

UPDATE: I was told that we've seen this issue before and proposed to check if this solution helps, so kindly review and let me know if it works.

[sirdeekay]

I disabled the Security Signature, rebooted and confirmed it was off via a Get-SmbClientConfiguration:
RequireSecuritySignature : False

Unfortunately I still get the same error. I just tried switching my NAS back to SMB 2 (from 3) to be sure it's not related to SMB 3 - still get the same error messages though.

Thanks for the suggestions though!

[sirdeekay]

I just found out I can enter random stuff into the credentials field - it'll accept anything. Which further confirms I shouldn't need credentials I guess.

[Dima P.]

Thanks for the heads up - getting back to QA team.

[sirdeekay]

Did some more testing. If I enter something into the credentials field and click populate it works. I can then proceed to uncheck the credentials and it will still work. Even after restarting Veeam. Restarting the computer breaks it again though.

[Dima P.]

Looks like a bug (definitely not a feature ). I'll follow up shortly.

[clifton23]

I too have this issue. I know not much of a help by stating that but I am willing to help any way I can!

[Dima P.]

Clifton,
The case is still under investigation. Can you clarify, have you tried the workaround described above?

[GBsysman]

Configuring a Dell DR6300 with Veeam 9UP1 on WinSvr 2012 I had this happing. Was resolved by editing the registry and changing the credential format. I used hostIP\sharename for mine. See the instructions below:

These registry values must be created on the the SMB client, which is specified in the repository settings as “Gateway server”. If the gateway is set to “automatic”, add these registry values to all Windows servers managed by Veeam Backup & Replication.

NetUseShareAccess:
For Veeam B&R 8.0.0.917 or later, the following registry value allows Data Movers to open backup files by a resilient method similar to the Windows net use command.

Key: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication\
DWORD: NetUseShareAccess
Value: 1

Note: If credentials are required, specify Domain\User or Host\User in the repository settings. .\User credentials are not supported with NetUseShareAccess. For example, specify “NAS-01\Admin” instead of “.\Admin”.

[Dima P.]

Hi GBsysman,

Sorry for confusion, but does this solution (and your post) apply to Veeam Endpoint Backup? Thanks.

[ktnrajput]

Thare is not option for password save, we we setup backup job

[Dima P.]

ktnrajput,

Can you please elaborate? Veeam Agent for Windows saves the access credentials in order to perform scheduled backup to the repository.

[edgar48]

I had a similar problem and got always the Message " The specified Server can not perform ... "
for me the following worked:
I had noted the user name just as user name.
In the Help center I found: If the network shared folder requires authentication, select the This share requires access credentials check box and specify a user name and password of the account that has Full Control access permissions on this shared folder. The user name must be specified in the down-level logon name format. For example, DOMAIN\UserName or HOSTNAME\UserName.
So I entered Server Backslash username and everything was fine.

[R.Boening]

You are trying to use an unsecured NAS with Windows 10? The problem might be Windows itself, not VEEAM.
Try setting this reg-key:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\LanmanWorkstation]
"AllowInsecureGuestAuth"=dword:00000001

Explanation:
https://support.microsoft.com/en-us/hel ... indows-ser

tl;dr
Windows doesn't allow connections on unauthenticated SMB2 shares (or guest-authentificated) since version 1709. Set this registry key, reboot, try again. It's worth a try, this change of behaviour "killed" a lot of hardware-storages back in the days.

[Dima P.]

Good catch, thank you for sharing Ralf!