Microsoft: Here's what caused our cloud outage this week

Microsoft officials are starting to share some details with customers and partners about what led to several cloud-service outages this week.

On August 17, many North American users of Microsoft Office 365 and SkyDrive were unable to access their email and calendars due to a three-plus-hour outage.

Some Dynamics CRM Online users also experienced service problems that day, but Microsoft execs are not saying the two sets of issues were due to the same root cause. The Dynamics CRM team has declined to provide information on what led to Wednesday’s outage or on how many users were affected. (Microsoft officials have said that Microsoft is planning to add CRM Online to the company’s hosted Office 365 suite — which currently includes Microsoft-hosted Exchange, SharePoint and Lync — before year-end.)

Update: The Dynamics team sent this update via a company spokesperson:

“The root cause of the Microsoft Dynamics CRM Online service has been identified as a site configuration issue. A configuration change was made in all data centers that should prevent this from happening again. This was not a complete outage and separate from any other service issue experienced by customers. ”

 While not sharing exact details, Microsoft officials are attributing the Office 365 problems to “a networking interruption” in one of its North American datacenters. One of my contacts said he believed faulty Cisco networking gear was the culprit — something Microsoft a Microsoft spokesperson didn’t confirm (or deny) when I asked.

Microsoft sent out notes to Office 365 customers using the affected Microsoft-hosted services on August 18 informing them of their initial findings and plans to credit affected users with 25 percent of their monthly invoices. Here is a copy of the note Microsoft e-mailed to customers:

ZDnet has the details HERE!