Hi,
We plan to migrate our 7 VMs from classic to Azure Resource Manager. How do we know the downtime that will occur during the process?
Hi,
We plan to migrate our 7 VMs from classic to Azure Resource Manager. How do we know the downtime that will occur during the process?
For most VM configurations, only the metadata is migrating between the Classic and Resource Manager deployment models. The underlying VMs are running on the same hardware, in the same network, and with the same storage. The management-plane operations may not be allowed for a certain period of time during the migration. However, the data plane continues to work. That is, your applications running on top of VMs (classic) do not incur downtime during the migration
Reference here: migration-classic-resource-manager-overview
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Adding more info to the above response, There won't be any downtime. However, for better migration experience, it is suggested to take downtime for an hour or two just to make sure if something doesn't go as expected, We have sufficient time to troubleshoot the issue.
How long will the management-plane downtime be?
It depends on the number of resources that are being migrated. For smaller deployments (a few tens of VMs), the whole migration should take less than an hour. For large-scale deployments (hundreds of VMs), the migration can take a few hours.

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