This post is a part of the nine-part “What’s New in Windows Server & System Center 2012 R2” series that is featured on Brad Anderson’s In the Cloud blog. Today’s blog post covers [description of the specific technology covered in your engineering blog post] and how it applies to the larger topic of “Transform the Datacenter.” To read that post and see the other technologies discussed, read today’s post: “What’s New in 2012 R2: IaaS Innovations.”
This blog discusses the virtual machine (VM) deployment enhancements introduced in System Center 2012 R2 Virtual Machine Manager (VMM). (This information is focused on RTM features.)
Prior to this version, VMM exclusively used BITS (Background Intelligent Transfer Service) to transfer VMs from VMM library to hosts for VM deployment. However with large environments using Hyper-V and VMM managing large number of VMs, deployment time is essential.
With VMM 2012 R2, we optimized the speed for VM deployment from VMM library by leveraging Offloaded Data Transfer (ODX). Many large environments use SAN storage. ODX is a feature introduced on Windows Server 2012 which automatically orchestrates and optimizes the use of SAN storage by using tokenization on reads and writes without using buffers. With this capability, copying the VM can offloaded to the SAN device which decreases the server cpu utilization and decreases network bandwidth consumption which provides faster VM deployments. To use ODX, SAN storage must support this feature.
For more detailed information about ODX, please refer to the following articles on MSDN.
So how does it work?
ODX is part of the Windows Server fast file copy (FFC) feature. VMM deployment uses FFC or BITS to run the VM copy. To leverage ODX capability, following are pre-requisites.
Prerequisites as follow:
- Only for new VM deployment from the VMM library
- RAA (run as account) on source and target
- VMM and the hosts (source and target) must be on the trusted domain with no firewall among the environments.
- VMM R2 agent
- VMM R2 Server
- Windows Server 2012 and above
- ODX supported SAN storage
In deploying a VM, as a default, FFC is turned on automatically. FFC provides 2 methods of copying: ODX and network. When copying the VM, FFC will initially start with ODX. ODX can support inter and intra lun copies.
If ODX is not supported on SAN storage, the FFC engine will revert to network base transfer. This VM deployment using FFC has built-in resiliency while transferring data. If ODX and network base transfer has issues, FFC can revert to BITS.
This feature will be inclusive with differencing disk feature in the RTM timeframe.
The System Center VMM 2012 R2 improved rapid provisioning for VM deployment from VMM library using ODX and FFC. Here are some of the highlights:
- Increases VM deployment performance by offloading the cpu and network utilization to ODX supported SAN storage. (Seen 20-30% increase in performance for network.)
- With faster deployment, this can lessen interrupt to the host and shorten windows of maintenance.
- Built-in resiliency while copying VHD to host.
For more information about ODX supported vendors, please refer to the following site.
To see all of the posts in this series, check out the What’s New in Windows Server & System Center 2012 R2 archive.