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Improved SLA for Azure Virtual Machines

Up until now, Microsoft has guaranteed a 99.5% uptime SLA for IaaS (Infrastructure as a Service) virtual machines. While this level of uptime is very good, it is not enough for critical applications which require 24×7 access. An online retail app on Black Friday dealing with any downtime can mean big losses in revenue.

Why was there a 0.5% downtime expectation? When it comes down to it, the Azure servers which are hosting virtual machines are running Windows (of some sort). As such, they occasionally need to be patched with security and vulnerability updates. Just like any Windows machine, Windows updates often require a reboot. When these Azure hosts required a reboot, all of the virtual machines they were hosting would become unavailable.

Previously, in order to achieve a guaranteed uptime SLA higher than 99.5%, you would need to run multiple virtual machines in an availability group. For small businesses and small installations, this effectively doubles your costs and complexity.

This week, Microsoft’s Cory Sanders announced “a new 99.9% single-instance availability SLA to better support applications that cannot easily scale beyond single VMs”. There is a prerequisite however: All storage disks should be using the faster and higher priced premium storage. Premium storage allows up to 80,000 IOPS and throughput speeds up to 2,000 MBps.

This is just one more example of how the Azure cloud is ever-evolving, and getting better all the time.

 

About the author

Robert Borges

About Robert...

I have been in the IT industry since 1993 focusing mainly in networking. Though I got an early start as an amateur computer enthusiast, and wrote my first database app at age 12, I started my professional career working in the MIS department of one of the largest liquor distributors in the northeast. I started out there as a systems operator on the company’s two mainframe systems. From there I moved into PC support, and help design and implement the company’s first client-server network… This was back in the days of Win NT 3.51. I also worked on my first migration to NT 4.0 back then.

From there I went on to work with Novell 3.x and 4.x along with Windows domains and active directory environments. Working my way up from technician, to specialist, to administrator, and eventually all the way up to Sr. Engineer. I spent many years working for consulting firms, 9 of which I owned and operated my own firm.
Over the years, I have worked with (at an expert level) various versions of: Windows client and server operating systems (including Windows 7 and Windows Server 2008 R2);various virtualization technologies (Hyper-V, Virtual Server, Virtual PC, VMware, etc…); MS-SQL server 6.5- 2008 R2; Exchange 4-2010, and much more.

I am now Director of Information Systems at Bay State Integrated Technology focusing on cloud computing and IT service, with expertise in: IT Infrastructure & Architecture, IT Security, and Cloud Computing platforms & technologies (SaaS, PaaS, and IaaS).

I am in a constant state of learning about new products, and new versions of products. Many of which we end up implementing in lab environments and sometimes for our clients. I have a pretty broad range of expertise and experience. It is my goal to share some of this experience on this blog to help enrich the IT community.

Permanent link to this article: http://www.robertborges.us/2016/11/cloud-computing/improved-sla-for-azure-virtual-machines/