CmdID / az / az vm / az vm availability-set
az vm availability-set start-migration-to-vmss
Start migration operation on an Availability Set to move its Virtual Machines to a Virtual Machine Scale Set. Azure CLI reference
2 options Its page in the Azure CLI reference
Options
--availability-set-name, --name, -nThe name of the availability set.--vmss-flexible-idSpecify resource id about the Virtual Machine Scale Set that the Availability Set should be migrated to.