While the final release of Windows Server 2016 isn’t expected to be until early next year, Microsoft has been steadily releasing Technical Previews of the new server OS since October 2014. The most recent Technical Preview, TP3, introduced a number of new and interesting features that we’d like to share with you.
As of right now, Microsoft supports two different container models: Windows Server Container and Hyper-V Containers. Windows Server Containers run as applications on top of the host OS.
Hyper-V Containers will be completely isolated virtual machines (VMs) that incorporate their own copy of Windows kernel. Hyper-V Containers will make it possible to do nested virtualization within Hyper-V. The new PowerShell cmdlets also give an alternative to Docker commands to manage containers.
Windows Server Containers will be an embedded feature of Windows Server 2016 and work with the Docker ecosystem. This means that if you want to run a Linux container image on Windows, you’ll need a Linux VM.
Nano is a core piece of Windows Server, making it incredibly minimal—so minimal that it doesn’t have any direct user interface besides the new Emergency Management console. Nano instances are managed remotely using Windows PowerShell to include the process of adding new roles.
A Nano instance only uses about 512MB of disk space and less than 256MB of memory. This makes a big difference when building VMs on top of Nano. The Emergency Management console allows you to view and fix networking issues directly from the Nano Server console. Nano Azure VM instances can also be created with a PowerShell script and can now run ASP.Net v5 applications using CoreCLR.
PowerShell will see a significant number of new cmdlets focused on specific functionality. Those of interest include:
- 21 DNS-related commands
- 11 for Windows Defender
- 36 for Hyper-V, 17 for IIS administration
- 141 commands related to the Network Controller
The other big push for PowerShell in the new OS relates to Desired State Configuration (DSC). Microsoft has done a lot of work to make DSC the tool for initially configuring and maintaining not only Windows Server, but also Linux servers. Plus, when you throw in the new package manager service, GetOne, you have tons of new PowerShell-driven possibilities.
Windows Server 2016 gives you the ability to replicate entire volumes at the block level. You can also choose between synchronous and asynchronous replication.
This feature is primarily designed to aid in disaster recovery scenarios where a backup is needed for a quick fail-over. The OS supports both server-to-server and cluster-to-cluster replication.
Storage Spaces Direct
Storage space has taken a step further in Windows Server 2016. The new feature is called Storage Spaces Direct, and it gives you the ability to build a highly available storage system using only directly attached disks on each node. (A minimum of four nodes must be available to create a cluster.) It also takes advantage of new hardware like NVMe SSDs, while still supporting older SATA-based hardware.
ReFS as Primary File System
In Windows Server 2016, ReFS has been made the preferred file system for Hyper-V workloads. This means you should see new VMs with a fixed size VHDX being created at lightning fast speeds. The same advantages apply when creating checkpoint files and to merging VHDX files when you make a backup.
One thing to keep in mind is that ReFS allocates the storage for these operations without initializing it, meaning there could be residual data left over from previous files.
Hyper-V Rolling Upgrade
Windows Server 2016 supports rolling cluster upgrades from Windows Server 2012 R2 so you can perform upgrades without having to take down the cluster or migrate to new hardware. This should help make upgrading less painful for production environments.
The process is similar to before, in that individual nodes in the cluster must have all active roles moved or evicted to another node to upgrade the host OS. The difference is that all members of the cluster will continue to operate at the Windows Server 2012 R2 functional level—as well as support migrations between old and upgraded hosts—until all hosts are running the new OS. You can then upgrade the cluster functional level by issuing a PowerShell command.
Hyper-V Hot Add NICs and Memory
With Windows Server 2016, you can add network adapters while the VM is running. VMs with fixed amounts of memory can also have memory added while running. Not having to take your VM offline to make these configurations will certainly lessen your downtime.
Convergence is designed to help hosting providers merge traffic from multiple tenants to reduce the number of network interfaces. This can also reduce the required number of network ports by as much as half.
Packet Direct focuses on increasing efficiency across workloads to include everything from small packets to large data transfers.
Network Controller provides a central point for monitoring and managing network infrastructure and services. Other enhancements include:
- An L4 load balancer
- Enhanced gateways for connecting to Azure and other remote sites
- A converged network fabric supporting RDMA and tenant traffic
Storage QoS Updates
Windows Server 2016 allows you to centrally manage Storage QoS (Quality of Service) policies for groups of VMs and enforces them at the cluster level. This helps when multiple VMs make up a service and should be managed together.
Get-StorageQosFlow, a PowerShell cmdlet, provides a number of options to monitor the performance related to Storage QoS.
As the release of Windows Server 2016 continues to grow nearer, expect even more tweaks, updates, and changes to follow.
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