Crash-consistent snapshot of has been created. Cannot contact the Windows VSS agent via port 443.

[willholmes]

We are currently running a proof of concept Veeam for Azure trial in our tenant, we currently have 6 Azure VM's that are being backed up. Three of these Six machines are displaying the following warning message.

Crash-consistent snapshot of has been created. Cannot contact the Windows VSS agent via port 443. Proceeding with the crash-consistent snapshot.

It is worth noting that the 3/6 machines that are giving this message are physical to Azure migrated machines, the 3/6 that are working fine are machines that were spun up in Azure. I have disabled windows firewall on the machines to see if this helps but it has not.

Case #06060574

[nielsengelen]

Hi,

Did you assure that this port is also open via the Azure portal?

[willholmes]

I can confirm the port is open via the Azure NSG.

[willholmes]

For further info, there are 6 machines currently being backed up in the Veeam PoC, 3 are creating crash-consistent snapshots and 3 are not. The 6 machines are all in the same NSG, Subnet, VLAN, the difference between the 2 sets are that the 3 that are failing used to be physical machines that have since been migrated to Azure.

I have disabled the Windows Firewall entirely on the failing machines and previously tried creating inbound and outbound rules for port 443 but thought I would eliminate the Windows Firewall from my enquiries by turning off completely.

I have also tried playing with the VSS Service, setting it to both automatic and manual without success. I am stuck for ideas now.

[willholmes]

Further info, after trawling the windows logs it appears there is a recurring message on the failing servers.

Faulting application Veeam.Azure.Vss.Agent.Windows.exe, version 5.0.0.579, time stamp 0x6216cb5c, faulting module KERNEL32.dll!GetCurrentProcessorNumberEx, version 6.0.6003.20708, time stamp 0x5e0acab3, exception code 0xc0000139, fault offset 0x00000000000b6688, process id 0x1bb0, application start time 0x01d9843af296dd1e.