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1. Export VM when we are stopping the VM.
   
   Pros
   
   1.  In this case we  have to perform the costly export operation only when it is needed(when we cannot avoid).
   2. VM snapshots will be fast as then it needs to keep only differential data.
      
      
   Cons
   1. stop will get affected, which we can make asynchronous and export VM only when the VM snapshots has been taken on that VM.
   2. What will be done if VM is started before the export operation has been completed?
   3. What will happen if primary goes down in middle of export operation or export operation has not yet started?
      1. whenever host or primary comes up first export the VM then delete it, if it has snapshots
      2. What state of that VM will be returned in hostVMstatereport for vmsync?
         
         
2. Export VM at every snapshot
   
   Pros
   1. Probability of stop operation will not get affectedbeing affected will be low. Will only be affected when stop operation occurs in the process of exporting VM.
   
   Cons
   1. VM snapshots will be slow

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Note: Importing VM will not be costly operation assuming that exported will be kept on primary and then will be imported as in place

Failover Clustering and Hyper-V VSS

The Hyper-V VSS writer does not give any consideration to VMs that are part of a failover cluster. During both the "Saved State" method backups and all restores, the VM would be put into the saved state or deleted entirely. This would be seen as a failure by the clustering service and cause the applications on those nodes to be failed over to other nodes. To avoid this during "Saved State" backups, the VM state must be saved using the clustering service. To avoid this during a restore, the resources on the VM would need to be taken offline.