Virtual Machine Protected using Azure Site Recovery keeps on going to Resynchronization State randomly and then ReSynch will also Fail


This Post will take you through an issue where a VM Protected using ASR in a Hyper-V to Azure scenario, keeps on going in a Resynchronization state randomly. And when we try to ReSynch, it fails


We see the below Error for the VM on the Hyper-V Host On-Prem:




And then the ReSynch was also failing with the Error below:




While reviewing the configuration, we came to know that this VM had two Disks, the OS Disk was of around 100 Gigs and the Data Disk was Exactly 1 TB in Size.

According to the Article below the Maximum Disk Size supported for the Data Disk in ASR is 1 TB: 


So, looking at the above limitation of ASR, we decided to Shrink the Data Disk Size by around 100 GB, so that it can come down to 900 GB. And as soon as we did that, we did not see the VM going into the Resynchronization state anymore.

We monitored it for a few days and we still didn’t see any issues.



Nitin Singh

Support Escalation Engineer

Microsoft Security and Manageability Division