Storage Spaces Direct in Windows Server 2019

Storage Spaces Direct (S2D) is the award-winning software-defined storage (SDS) tecnhology that was first introduced in Windows Server 2016. Since that moment, S2D has become my one of the favourite and frequently used role in Windows Server (on-premises and even in Azure).

Windows Server 2019 that is going to be generally available in the second half of this year (September or October – in accordance with WS 2012-2016 release dates) continues to develop S2D by adding new features. Why don’t we discuss them right now?

TIP: Windows Server 2019 preview build is available here

Scalability

More volumes, bigger capacity per server and cluster

Storage Spaces Direct Scalability in Windows Server 2019

USB Witness

Storage Spaces Direct can be configured with just two nodes. However, we will need to design witness placement to protect our cluster from unexpected failure (in other words, we should achieve quorum). In Windows Server 2016, you can place witness on a file share, cloud (details here) or disk witness (it’d be very strange if it was actually used in S2D clusters). What about customers who don’t have any AD infrastructure or Azure/Internet access? Here is a breakthrough – USB Witness.

usb witness windows server 2019

In short, you will be able to configure a true two-node S2D by using USB thumb drive connected to the router that is already used for VM/management traffic between nodes, for instance. Other two network interfaces (shown on the picture above), could be RDMA-adapters (recommended and supported) or Thunderbolt (POC, Project Kepler-47).

Simply insert the USB drive into the port on the router, set the share name and access information, configure witness in PowerShell: Set-ClusterQuorum -FileShareWitness \path\ -Credential  and you are ready to go.

TIP: the router should support SMB2+ and USB. And, given that a witness.log is a quite small file (just kilobytes), you can use any-sized USB drives. The list of the supported routers will be available later.

Data Deduplication

ReFS  is the recommended file system for S2D, improves VHDX creation/expansion speed (enables Accelerated VHDX operations), provides higher stability by detecting corruptions and allowing you to repair them with no volume downtime. However, some features such as ODX, Data Deduplication are not supported by ReFS in Windows Server 2016.

Starting with the Windows Server 2019 (1709 and later), Data Deduplication has been fully supported for ReFS. It means that you no longer need to choose between NTFS and ReFS file systems while planning S2D volumes. Create ReFS volume, enable Data Deduplication (PowerShell/Windows Admin Center), and then check the savings of storage space (use PowerShell and Get-DedupVolume cmdlet).

data deduplication s2d windows server 2019

Proactive outlier detection

It was quite challenging to investigate  performance issues in S2D in Windows Server 2016. We had to use PowerShell or performance counters (+VMFleet) to get a full picture of our setup’s behavior. Windows Server 2019 significantly simplifies that. S2D now records the outcome (success/failure) and latency (elapsed time) for every read/write IO to every drive without any performance impact. Therefore, drives with latency/outcome issues will be marked in PowerShell and Windows Admin Center as “Abnormal Latency” status. In addition, you can organize pooled drives into peer groups, and then compare latency against peers to quickly find any bottlenecks (new cmdlet: Get-PhysicalDiskIoReport).

This azure-inspired mechanism works on the lower level than performance counters and enabled by default for every SATA,SAS,NVMe drives.

latency outlier detection s2d 2019

Others

-Faster mirror-accelerated parity volumes (~x2)

-PMEM (Persistent Memory) drives support (Intel Optane/NVDIMM-N) for use as cache and capacity

-Deep integration with Windows Admin Center (a free HTML5-based management interface for entire Windows Server infrastructure. We’ll look at this a bit later)

System Center 1807 is available

It has recently been announced that a new semi-annual channel release for System Center is available. As you can see in the following picture, the new System Center 1807 is the last release before GA of SC 2019. So, my recommendation is to implement this release and test it before going further . In short, you have a plenty of  time to evaluate the newest SC and prepare your staff for SC 2019 deployment in production.

system center roadmap

TIP: SC 1807 is an update release for SC 1801. To apply System Center, version 1807 you will first need to download SC 1801

System Center 1807 provides updates to the following products:

:: Operations Manager

:: Data Protection Manager

:: Service Manager 

:: Orchestrator + SMA

:: Virtual Machine Manager

In this post, we will cover the major changes for VMM.

Storage Space Direct Management

With Virtual Machine Manager 1807, you will now be able to patch and update the nodes of a Storage Spaces Direct cluster with the orchestration of the update process performed by VMM.  You can update individual S2D hosts or clusters against the baselines configured in windows server update services (WSUS)

VHD Placement

When you add a new VHD to the existing VM, you can now define CSV path (a new volume) for that disk to eliminate problems with storage space. Prior to VMM 1807, a new VHD of an existing virtual machine would be placed in the same CSV as the other VHDs, aggravating the problem if the CSV was already running high on utilized storage.

vhd placement csv vmm 1807

Convert SET switch to logical switch

VMM 1807 allows you to convert a switch embedded teaming (SET) switch to logical switch by using the VMM console. In earlier versions, this feature was supported only through PowerShell script.

Display of LLDP information for networking devices

VMM 1807 supports Link Layer Discovery Protocol (LLDP). You can now view network device properties and capabilities information of the hosts from VMM. Host operating system must be Windows 2016 or higher. DataCenterBridging and DataCenterBridging-LLDP-Tools features have been enabled on hosts to fetch LLDP properties

lldp vmm 1807

VMware host management

VMM 1807 supports VMware ESXi v6.5 servers in VMM fabric. This support facilitates the administrators with additional flexibility in managing multiple hypervisors in use.

To evaluate SC 1807, you can download SC 1801 from here , and then update to 1807 (SAC) + it also will be available @MSDN.

In addition, VMM 1807 has received SQL Server 2017 support.

TIP: VMM 1807 update package for VMM 1801 can be obtained here