When a node fails, the system automatically stops and deallocates the failed node, which might result in losing diagnostic information. You cannot recover a failed node unless it is stopped and deallocated, as the Azure platform restricts detaching NICs.
On a Vantage multi-node system, NFR automatically replaces the failed nodes with the same number of available hot standby nodes (HSNs). If there are no HSNs or not enough available HSNs, NFR automatically spins up one or more replacement nodes, detaches the network-attached storage of the failed node, reattaches the network-attached storage to the new VM, migrates the secondary IPs from the failed node NIC to the new VM NIC, and reinstates the configuration. The replacement node is deployed from a snapshot of the active (control) node.
NFR takes longer than a typical TPA reset. If your node does not automatically recover after 10 to 15 minutes, check the deployment logs in your Azure resource group.
For assistance, contact Teradata Services.