Windows Server Insider Preview build 16257 is now available - here's what's new

Almost a month ago, Microsoft released the first Insider Preview for Windows Server, build 16237. Now the second build, 16257, is seeing the light of LCD.

Added to the list of downloads are Remote Server Administration Tools (in x86 and x64 flavors), which allows users to "remotely manage and administer Insider builds of Windows Server via GUI tools." In order to use these, you'll need to be on a Windows 10 client build of 16250 or greater.

The new Server build contains a couple of big new features, including Delivery Optimization for updates and the Windows Subsystem for Linux.

Here's the changelog for build 16257:

Windows Subsystem for Linux (WSL) is available on Windows Server

• Windows Subsystem for Linux (WSL) is now available on Windows Server along with a compliment of Linux distributions.'

• Test WSL on Windows Server. WSL runs unmodified Linux (ELF64) binaries natively. With the additions of WSL you can run node.js, Ruby, Python, Perl, Bash scripts or other tools that expect Linux behaviors, environment, or filesystem-layout, the ability to install and run Linux with WSL expands the tools at your disposal on Windows Server.

• At this time, WSL does not support persistent Linux services (such as daemons and jobs) as background tasks. To enable WSL and install a Linux distribution, see Enable the Windows Subsystem for Linux and Install a Linux distribution in the Windows Server 2016 Installation Guide on GitHub.

• Read more in this blog or follow the installation guide to try it out.

Delivery Optimization is available for Windows Server

Delivery Optimization has been the main downloader of Windows Update and Windows Store content since the Windows 10 Anniversary Update, providing faster and more reliable downloads. Starting in the latest builds for Server, Delivery Optimization is now the downloader used by Windows Update on Windows Server.Delivery Optimization can also provide Peer-to-peer bandwidth optimization between Windows Server machines. To enable peer-to-peer downloads open Settings -> Update & Security -> Advanced Options -> Delivery Optimization and turn ON the toggle to “Allow downloads from other PCs”.

These 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 a 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 ongoing 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

To install the new Windows Server Insider Preview build, you can download it from here. You'll need to use the following keys, which can be used throughout the pre-release cycle:

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

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