Microsoft will be crediting customers affected by its September 4 cloud outage and will work to improve its cloud storage resiliency, according to its preliminary analysis of the incident.

Microsoft has made available publicly a preliminary root cause analysis (RCA) for its September 4 cloud outage that impacted customers worldwide. The Azure engineering teams are continuing to investigate the incident and are saying they will provide a more detailed analysis “in the weeks ahead.”

Impacted customers will receive a credit based on the Microsoft Azure Service Level Agreement in their October billing statements, Microsoft officials said in the post-mortem report.

On September 4, as I blogged originally, a lighting strike hit near Microsoft’s South Central US datacenter region, knocking out a number of Azure services, as well as Office 365, which authenticates via Azure Active Directory, for many Microsoft customers worldwide.


Lighting Strike will do it every time.