Microsoft attributed the March 12 glitch affecting Hotmail and Outlook.com to a temperature spike in one of its data centers. Many users said they had no access to the services on Tuesday night and into Wednesday morning. SkyDrive was also affected.
According to a Wednesday Outlook blog post by Microsoft VP Arthur de Haan:
“On the afternoon of the 12th, in one physical region of one of our datacenters, we performed our regular process of updating the firmware on a core part of our physical plant. This is an update that had been done successfully previously, but failed in this specific instance in an unexpected way. This failure resulted in a rapid and substantial temperature spike in the datacenter. This spike was significant enough before it was mitigated that it caused our safeguards to come in to place for a large number of servers in this part of the datacenter.”
Many Hotmail and Outlook users have reported on-going issues with the services since January, when Microsoft started migrating Hotmail users over to Outlook.com. Making things harder to track is that not all these issues show up on the Microsoft Live Status page which only reflects problems affecting a “significant” number of users. Microsoft told users who are having issues to log into their account to see for more information on their status.