Allow Synology Active Backup for Business to Access Hyper-V

This has tripped me up twice, so time to blog it. Synology has an article on setting up Hyper-V for access from Synology:

Which Windows services on Hyper-V servers are required for Active Backup for Business?

In spite of following that, I kept getting authentication errors (though I knew my username and password were good.)

The first error you may see is “Failed to connect to host.” In my case, this simply meant that the NAS could not resolve the Server Address. To fix this, you can either use an IP address or add the Server Address to your DNS server.

The next error is more difficult:  “Unable to perform the action … due to failure to access the hypervisor. Make sure the account you signed in with has the right permissions.”

I knew the username and password were correct; I could log on with the same credentials and administer Hyper-V on the machine.

My Hyper-V servers run as as workgroup machines, not domain-joined, and I recalled that that might require some special configuration for remote management, I spent considerable time trying to allow remote management (following articles like this one), but finally the only thing that was required was to run winrm quickconfig on the Hyper-V host and follow the prompt to enable remote management:

Once I did that, Synology Active Backup was immediately able to connect to the Hyper-V server:

Update October 6, 2023

If the User profile mountable check fails:

open Windows Defender Firewall with Advanced Security, go to Inbound Rules, and enable the ”File and Printer Sharing (SMB-In)” firewall rule:

I have one 2022 Standard server has several extra “Private” rules for File and Printer sharing, including an SMB-In rule, but on a couple of 2022 Essentials servers, the extra rules are not there so I had to enable it manually.

Update January 26, 2024

More gotchas. I have a domain-joined Windows 10 machine running Hyper-V that I wanted to use to test a restore. I set up a local ActiveBackupAdmin administrative user on that machine but could not for the life of me get the Synology to connect using that credential. Maybe a domain-joined maching requires connecting with a domain user?

Finally I provided domain admin credentials in the form domain\user. The Synology connected immediately to the maching, then quickly failed, telling me that it won’t connect to Windows 10: