Trap 1: Enable guest-level Windows event collection on a random virtual…
Guest-level Windows event collection on a single VM uses the Azure Monitor Agent or diagnostics extension to gather OS-level logs such as System, Application, and Security events from that machine's own operation. It does not capture any telemetry from the Azure Storage service itself, so storage write failures due to account-level throttling, network issues, or SAS token problems remain invisible. Additionally, selecting a random VM likely unrelated to the incident yields no useful signal, and guest events are irrelevant to subscription-wide control-plane changes like role assignments.
Trap 2: Turn on NSG flow logs for every subnet in the subscription.
NSG flow logs capture IP traffic flowing through a network security group, recording five-tuple information (source/destination IP, port, protocol), and allow/deny decisions at the network layer. They might show whether a VM could reach the storage service, but they contain no information about the storage account's internal handling of a write operation—such as authentication, authorization, or service-side throttling. Turning on flow logs for every subnet generates significant cost and noise, and still leaves the control-plane role-change trail completely absent.
Trap 3: Use Azure Advisor recommendations as the source of telemetry.
Azure Advisor recommendations are precomputed, curated insights based on periodic assessment of resource configuration and usage—they surface actionable guidance like performance suggestions or security best practices. As a consumer of telemetry rather than a source of raw logs, Advisor does not emit streamable events that can be queried for the exact timestamp, operation, and error details of a storage write failure. It also cannot provide an audit trail of role assignments or key changes, so it is unsuitable for an incident investigation where traceable raw data is required.