Microsoft has issued an apology to customers who were affected by the mass-outage of its cloud services.

Writing on the Azure blog, Jason Zander, CVP of Azure, said: "I want to first sincerely apologise for the disruption this has caused. We know our customers put their trust in us and we take that very seriously."

It seems the outage, which lasted for at least 11 hours from Monday to Tuesday, was caused by a cloud storage update Microsoft was rolling out.

Zander said: "I want to provide some background on the issue that has occurred.

"As part of a performance update to Azure Storage, an issue was discovered that resulted in reduced capacity across services utilizing Azure Storage, including Virtual Machines, Visual Studio Online, Websites, Search and other Microsoft services.

"Once we detected this issue, the change was rolled back promptly, but a restart of the storage front ends was required in order to fully undo the update."

He then reassured customers that Azure’s main priority is getting them back online promptly. Zander said: "When we have an incident like this, our main focus is rapid time to recovery for our customers, but we also work to closely examine what went wrong and ensure it never happens again."

The outage knocked out MSN.com, as well as the Windows Store service. Customers were affected right across the US, as well as North and West Europe, East Asia, and Southeast Asia. Japan was also hit by the crash.

It is confusing as to why Microsoft decided to issue the culpable cloud update to all of these regions at the same time. Frustrated customers have taken to the blog to criticise Azure and its response to the incident.

Christopher Webster, a law and policy analyst, said: "Azure wasn’t the only thing that failed – your crisis messaging let you (and us) down badly."

An anonymous poster was also not impressed with Azure’s response. They said: "Is Jason Zander trolling? That’s it? That’s the response to an 11 hour global outage? Are you kidding me?"