Released: 08 August 2017
Source: Announcing Windows Server Insider Preview Build 16257
Days Since Last Build: 26 Days (16237 on 13 July 2017)
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What's New
This release also includes the Remote Server Administration Tools (RSAT) packages. When installed on a Windows 10 client, RSAT allows a user to remotely manage and administer Insider builds of Windows Server via GUI tools. Valid on Windows 10 client builds greater than 16250.
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”.
Improvements and Fixes
None noted.
Known Issues
The background tasks infrastructure service (Bisrv.dll) may cause a system crash because of a null class pointer read error (0xC0000005) or a failfast corrupt list entry (0xC0000409) during a Distributed Component Object Model (DCOM) launch, or because of a critical process bug check (error code 0xC0000409, bug check 0xEF) in the host process for Windows services (Svchost.exe).
Calling into the firewall service may hang: Apps that call into the firewall, such apps that use networking, may become unresponsive until the user reboots because of an application hang end-task error (0xCFFFFFFF) in the Windows firewall API library (FirewallAPI.dll), which occurs when the library is blocked on an advanced local procedure call (ALPC) port while attempting to diagnose a connection failure and retrieve information.
Cluster Sets: A couple of key functionalities to enable end-to-end testing of Cluster Sets scenarios are not present in this build, so defer all evaluation of this scenario to a future build.
Bugcheck during volume creation: A stop error may occur during volume creation in a cluster. The recommended workaround is, after restarting the computer, to delete the volume and try creation again.
Bugcheck during volume repair: A stop error may occur during volume repair in a cluster. The recommended workaround is to restart the computer. No corruption or data loss is expected.