How do I keep a non-azure VM (New York Based) in sync with my Azure File Sync (US East 1) service after I failover the VM to a datacenter in California?

Question

Hi,

I have a non-azure based VM that resides in my company datacenter in New York. I have that VM synced up with Azure file sync to an Azure files storage based in US East 1. However, I'm having an issue when I test failover of the VM to our California based datacenter. I perform the failover using Zerto, but when the VM is failed over it loses sync completely with the Azure file service.

I've looked into this issue being a possible networking issue, but I've already ruled that out because I have routing built into azure that interconnects both of my company's datacenters in California and New York to Azure from US West 3 to US East 1.

I'm just looking for other possible causes as to why this is happening so I can come up with another solution for our company's business continuity model.

Thank you!

Answer 1

Hi Eric Andrade

Thanks for using the Q&A platform.

You're on the right track with your architecture, leveraging Azure File Sync for a hybrid file server. If your failover to the California data center causes the sync to break, but networking is verified, there are a few technical areas to investigate.

Each VM that participates in Azure File Sync must be registered as a server in the Azure File Sync service. When you fail over a VM using Zerto, you may be replicating the OS disk and configuration, but the underlying server identity (SID) used by Azure File Sync may no longer match. Azure File Sync registers machines with a unique ID, not just by name or IP.

I would recommend that after failover, re-register the VM with Azure File Sync using ServerRegistration.exe or uninstall and reinstall the Azure File Sync Agent, and link it back to the sync group.

If the VM in California has a different system time, it can cause authentication failures with Azure File Sync. Ensure NTP is working and synced to an authoritative time source.

Additionally, ensure the Storage Sync Agent version is the latest supported one for your OS, and it starts properly post-failover.

Find additional documentation:
https://learn.microsoft.com/en-us/azure/storage/file-sync/file-sync-deployment-guide?tabs=azure-portal%2Cproactive-portal#register-the-windows-server

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Regards,

Obinna.