Hi All :

   Throughout the development of Windows Server 2012, we have regularly pushed the scale boundaries as test resources and engineering schedule allowed. For example, in pushing Hyper-V scale to support up to 64 virtual processors per VM, it isn’t just replacing some static variables and retesting. There is serious engineering prowess that is brought to bear to ensure uniform and consistent scaling across the board such as:

  1. Virtual NUMA
  2. SR-IOV & Networking
  3. Live Migration
  4. Storage Optimizations (Have I mentioned we can deliver over 1 million IOPs from a single VM..? J)

    Scalability means systematically breaking through one scalability barrier only to find the next one, addressing that to ultimately achieve system balance. To that end, Windows Server 2012 is redefining performance and scale and the reason for its success has been the tremendous work cross-team to identify and mitigate these issues across the platform. To that end, I’d like to extend a huge thanks to all of the teams helped us achieve these goals including:

 

  >>  Windows Core Kernel, Storage, Networking, Hyper-V, Clustering <<

    Because the Windows Server 2012 scale limits have continuously grown throughout development, I want to make sure that everyone is using the same FINAL scalability numbers and present one more update courtesy of the Failover Clustering Team. With Windows Server 2012 RTM, we now support up to…

 

>> 8,000 Virtual Machines in a Cluster <<

 

Read that last sentence one more time.

 

    Yes , that’s right, 8,000 VMs in a cluster. To put that in perspective in terms of numbers for VMs per server in a cluster that translates to:

 

Nodes in 
  Cluster

Number of VMs
  per Server

8

1000

16

500

32

250

64

125

 

    As you can see, you could do an 8 node cluster with 1,000 VMs per server, but failing over 1,000 VMs per server will logically take some time and be dependent on a multitude of factors most of them storage related.Thus, the ability to support up to 64 nodes (twice as many as VMware) to disperse the load is significant.

 

Awesome.

     So, let’s take a look at the final scalability numbers for Windows Server 2012 Standard AND Datacenter Editions with Hyper-V enabled.

 

===========================================================================

Windows Server 2012 Standard/Datacenter Editions with Hyper-V Enabled

===========================================================================

 

 

Windows Server
  2008 R2

Windows Server
  2012

Improvement
  Factor

Logical Processors Per Host

64

320*

5x

Physical Memory per Host

1 Terabyte

4 Terabytes*

4x

Virtual Processors per Host

512

2048*

4x

Virtual Machines per Host

384

1024*

2.7x

 

 

 

 

Virtual Processors per VM

4

64

16x

Memory per VM

64 Gigabytes

1 Terabyte

16x

Maximum Virtual Disk

~2 TB

64 TB*

32x

 

 

 

 

Nodes in a Cluster

16

64*

4x

Virtual Machine in a Cluster

1,000

8,000*

8x

 

*= Industry Leading

 

 

      Enjoy !

      Justin Gao

      Microsoft (China)