I’m planning to do a vmware to hyperv migration using veeam instant recovery and my intended workflow is:
1- Start IR to hyperv
2- Shut down the vm on vmware and confirm it boots cleanly on hyperv
3- Leave the vm running on IR for a validation period
4- Run migrate to production to move the VM from the backup repository (qnap) to native hyperv storage
While the VM is running from IR, I understand that all new disk writes (delta changes) are redirected to a write cache stored on the veeam mount server
In this case the VM is a file server with active users accessing shared drives throughout the day so the write cache will continue growing both during the validation period and throughout the migrate to production process while the base disk data and delta changes is being copied to production storage
My question is: when migrate to production completes copying the base disk data and begins applying the accumulated write cache during the final stage, is there gunna required downtime for the VM or is the transition seamless from a user perspective?
The concern here is that migrate to production might take more than 12 hours since the provisioned hard disks on that VM are around 2tb in total so the cutover might happening during the day