ASR VMWare to Azure - Error: 78088

A while back I was working on Azure Site Recovery, preparing VMWare workloads for the cloud, this normally is a very straight forward process. You setup your environments, create the extra server you need, configure the vault on Azure and so forth. During such process I hit a snag by the little know name as Error 78088:

Failover failed with ‘HvrPreFailoverScriptExecutionFailed’ 
Azure error message: ‘WaitForScriptExecutionTask TrackAction caught exception. 
FMErrorcode: HvrPreFailoverScriptExecutionFailed, 
Message: prefailover workflow task: ScriptExecutionTask failed. 
An error occurred during data massaging’.

What this error means is that during Failover ASR tries to massage the data and prepare it for Azure, it does by looking for certain drivers. When any of these drivers are missing either not installed or in the proper location in the registry you will get the error labeled above.

The drivers are the following:


You can easily check if these drivers are installed by running the following command:

Get-Service -ServiceName driver

One thing note is that, it is alright if the driver is not running, as long as the driver is installed and you don’t get any red text you are fine with the driver.

The next thing to check are the following registry entries for all the drivers being present in all the listed registry entries:


If you notice that you are missing a driver, the easiest thing to do is to go another machine that has these drivers installed. If it does, go to the registry and export the drivers you are missing, and copy them to the machine missing the drivers. Once there import the registry files, but as always make sure to backup your registry (Warning!: I am not responsible for your registry breaking, again always do a backup before you modify your registry!) You will need to reboot your machine afterwards, and then check both if the driver is installed and in the registry.

This should resolve the error mentioned, just make sure that you give ASR enough time to resync and then try a test failover, as a way to spot errors early on.

Root Causes: One of the reasons that you may be missing essential drivers is if you migrated from a physical machine to VMWare and now are using ASR to migrate or DR to Azure.

Happy ASR’ing!


P.S. As always make sure to always backup your registries and do not just download drivers from any random page on the internet.