Microsoft releases the first Windows Server Insider Preview, build 16237 - here's what's new

Back in May, Microsoft announced that it would be introducing a new Insider Program for Windows Server this summer, complementing the current Windows 10 Insider Program that has existed since 2014. Today, the company released the first Insider build of the OS, which is build 16237.

Like all Insider Programs, it's designed so that customers can test the latest pre-release features, and also provide feedback to help shape future development.

Obviously, this is the first time that Server customers are publicly getting access to the Redstone 3 Development Branch, so there are a lot of new features. Here are the general scenario highlights that Microsoft outlined in its announcement:

Developers and Containers:

• New base container images (available on Windows Insider Docker Hub repo)

  • Optimized Nano Server base image (over 70% smaller)

    • The .NET team is providing an preview image based on Nano Server with .NET Core 2.0

    • The PowerShell team is providing a preview image based on PowerShell 6.0

  • Optimized Server Core base image (over 20% smaller)

• Support for SMB volume mounting

• Infrastructure for Orchestrators

  • Networking enhancements for on going Kubernetes work

  • Named pipe mapping support

• Bug fixes, performance enhancements

Cloud Guest:

• IIS

  • TLS info: administrators can make specific recommendations to default to HTTPS

• Disaster Recovery

  • Storage Replica Test Failover

• Guest + Host better together

  • vPMEM in Guest: Tenants can use and manage PMEM/SCM

  • Tenant-Aware VM Start Ordering: App Ready / OS Heartbeat for better load balancing

  • Guest RDMA

• Improvement in time accuracy

• Azure enlightened clusters – optimized to run on Azure IaaS

Cloud Host:

• Software Defined Data Center (SDDC) host
  • Security

    • Shielded Linux VM

    • SDN: Encrypted virtual networks

    • Secure clusters

    • SMB 1 disabled by default

  • Resiliency and Availability

    • SDN: Reduced downtime for tenant connections through gateways

    • Spaces Direct: Scoped Spaces to mitigate impact of multi-node loss

    • Spaces Direct: Marginal drive handling for predictive detection of drive failures

  • Efficiency

    • Data Deduplication available for ReFS

    • New Data Deduplication DataPort API for optimized ingress/egress

    • Space efficiency with ReFS Compaction

    • Performant Spaces Direct Multi Resilient Volumes (MRV)

  • Hyper-converged Scale

    • Cluster Sets: Significantly increases hyper-converged SDDC cloud scale by grouping multiple clusters into a larger fabric

  • Hardware support

    • Support for Storage Class Memory (SCM) in Spaces Direct

Here are the new features:

Persistent Memory can now be exposed to Hyper-V VMs:

• In this build, NTFS-formatted direct access volumes that are created on non-volatile DIMMs can now be exposed Hyper-V VMs. This enables Hyper-V VMs to leverage the low-latency performance benefits of Persistent Memory devices.

• Virtualized Persistent Memory (vPMEM) is enabled by creating a VHD file (.vhdpmem) on a direct access volume on a host, adding a vPMEM Controller to a VM, and adding the created device (.vhdpmem) to a VM. Using vhdpmem files on direct access volumes on a host to back vPMEM enables allocation flexibility and leverages a familiar management model for adding disks to VMs.

• PowerShell can be used for the creation and management of Virtualized Persistent Memory.

Battery Passthrough:

• With new additions to Set-VM, a PowerShell cmdlet, you can now enable and disable Battery Passthrough, a new feature. Battery Passthrough let your VMs have the same battery state as the host they are on. To use this feature of Set-VM, use the flag -BatteryPassthroughEnabled {$true, $false}. This option is only available for version 8.2 virtual machines.

Improvements to Container Networking:

• This build introduces enhancements to container networking to better support Kubernetes by adding support for multiple containers (w/out Hyper-V isolation) to a single Pod (Network Compartment) as well as only requiring a single endpoint per Pod for all traffic types (e.g. ingress and East-West)

• The Host Networking Service (HNS) now has support for creating ACL, NAT, and Load Balancing network policies for Container endpoints for fine-grained policy application.

RDMA for Trusted Guests:

• This build includes several enhancements for (Trusted) Guest RDMA to enable low-latency storage access with zero CPU usage by Trusted Guest VMs – this is ideal for running Windows File Servers in a Guest to accelerate file serving. Requires updated NIC drivers.

Improvements to Software Defined Networking:

• Encryption can be enabled for virtual network subnets to protect your traffic from anyone with physical access to the wire, including network administrators.

• Failover time for SDN gateways is improved. Now, you will observe much faster failover times for the gateways, even with high number of connections.

• Access control lists can be applied for infrastructure on logical subnets.

Improvements in Networking transports:

• 2X throughput improvement for single connection TCP and UDP performance in low latency intra-datacenter scenarios

• Default congestion control algorithm CUBIC for high speed networks

Improvements in HTTP(s):

• SSL throttling to enable predictable service for established connections, in the face of high incoming SSL traffic.

• Deterministic certificate updates for HTTPS enabling greater service availability.

Improvements in time accuracy:

• Pressing EU regulations in 2018 require strict time precision and traceability. Win32tm improvements in RS3 support greater time accuracy, and jitter is removed from the measurements that calibrate the service.

• New system event logging lets you archive time service data to support traceability compliance.

• System center monitoring now includes a new rule which lets you detect when a machine in your environment is out of compliance.

Nano Server optimized for Containers:

• Nano Server is now a container only option and optimized for containers, more information is available in the Delivering continuous innovation with Windows Server blog post. To optimize for containers, several features were removed that were in the Nano Server base image in Windows Server 2016, these include WMI, PowerShell, .NET Core, and the Servicing stack, which has significantly reduced the image size.

Server Core base image optimizations:

• The Windows Server Core base image has been optimized saving over 20% download and on disk space.

Any registered Insider can download the new build (there's a temporary issue with Azure AD accounts that signed up for Windows Insiders for Business), and you can grab it here. This particular build will expire on December 4, but Microsoft has provided keys that can be used throughout the pre-release cycle:

• Server Datacenter Core: B69WH-PRNHK-BXVK3-P9XF7-XD84W

• Server Standard Core: V6N4W-86M3X-J77X3-JF6XW-D9PRV

As with all Windows Insider Programs, Microsoft hopes that you will submit your feedback to the Feedback Hub.