Windows Server 2019 Preview Build 17650 Released
Windows Insider Program testers got a new preview build of Windows Server 2019 this week.
Build 17650 is available to testers of the long-term servicing branch product and the semiannual channel release product, Microsoft announced on Tuesday. The test release will expire on July 2, 2018.
This release features the use of a File Share Witness in failover clusters. There's also the addition of a Remote Desktop Session Host, which was lacking in earlier test releases.
Microsoft also reaffirmed that Storage Replica will be in the Windows Server 2019 Standard edition, and not just in the Datacenter edition. Storage Replica, used for disaster recovery, enables "synchronous and asynchronous block replication between servers or clusters," according to the announcement.
Its use with the Standard edition comes with limitations. It can only replicate a single volume that's up to 2TB in size and it only can "have one partnership," Microsoft previously indicated. Those limitations could change with newer Windows Server updates, the announcement suggested.
The File Share Witness enhancement in Windows Server 2019 promises to open failover cluster options for organizations. A File Share Witness is typically used as a "tiebreaker" when a split occurs between nodes in a failover cluster, according to an explanation by John Marlin, a senior program manager for high availability and storage at Microsoft. Some organizations, though, can't use this sort of setup. One reason is that it requires that the share "reside on a domain member that is in the same Active Directory forest." It has that requirement because it uses Kerberos for the Cluster Name Object (CNO), Marlin added.
That limitation goes away with Windows Server 2019, according to Marlin:
We can now create a File Share Witness that does not utilize the CNO, but in fact, simply uses a local user account on the server the FSW [File Share Witness] is connected to. This means no Kerberos, no domain controller, no certificates, and no Cluster Name Object needed. While we are at it, no account needed on the nodes.
Build 17650 has "two new enhancements" for using File Share Witness with failover clusters. One will block locations that use the Distributed File System since its use causes stability problems for a cluster. The second enhancement is the one described by Marlin, where the File Share Witness is not dependent on using Kerberos for the CNO. It will let organizations use File Share Witness even when there's poor Internet access, a lack of shared drives or "lack of a domain controller connection due to the cluster being behind a DMZ [demilitarized zone]," Microsoft explained.
Kurt Mackie is senior news producer for the 1105 Enterprise Computing Group.