Veeam SAN mode Backup failure

December 11, 2017 5 By Allan Kjaer

I was troubleshooting a strange Veeam backup problem. I could not get Veeam to do SAN mode backup.

The installation was.

  • vCenter 6.5 Update 1c
  • ESXi 6.5 update 1
  • Veeam B&R 9.5 Update 2
  • Backup server Windows 2012 R2
  • Backup Proxy server Windows 2016
    • Subsystem Device Driver Device Specific Module
  • storage IBM Storwize V7000 FC Hyperswap
    • VMFS-6 Datastores
  • hard Zoning in SAN switches

The backup was doing failback to NBD, very time running backup jobs on the proxy server.

I looked thru the log files on the Veeam B&R server and the proxy server, but there was no clue to what was wrong, only that it could not do SAN backup, and did a failback to NBD.

I tried:

  • remove Subsystem Device Driver Device Specific Module and Windows MPIO
  • format VMFS-6 datastore to VMFS-5
  • multiple rescan of the vCenter and Windows server i Veeam B&R
  • and other things

Nothing worked.

The Veeam solution is protected by at firewall, and at the end we did look at the firewall, for something we forgot to open, we has opened for TCP port 443 to vCenter, TCP port 902 to the ESXi hostx, DNS, NT and patch management. But what we saw was that the Veeam proxy, was trying to contact the Microsoft Certificate servers.

This is because we have changed the Certificate of the vCenter server, with a signed certificate from the Certificate server, and the Proxy server is not in the Active Directory, so the VDDK could not validate the vCenter certificate. So we opened TCP port 80 to the certificate servers.

I think that we also could have installed the Root CA + intermediate Certificate, but I did not have time to test that.


Tom Soghter, Principal Solutions Architect at Veeam Software, has written a comment with the explanation for this behavior,.Thanks.

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