Storage Spaces Direct Explained – Storage QOS & Networking


Storage QOS & Networking

Yo everyone…This is going to be a short blog post in this series. I am just covering Networking and Storage QoS as it pertains to S2D. There are the technologies the bind S2D together.

Storage QoS

S2D is using the Storage (QoS) Quality of Service that ships with Windows Server 2016 which provides standard min/max IOPS and bandwidth control. QoS policy can be applied at the VHD, VM, Groups of VMs, or Tenant Level. Benefits include:

  • Mitigate noisy neighbor issues. By default, Storage QoS ensures that a single virtual machine cannot consume all storage resources and starve other virtual machines of storage bandwidth.
  • Monitor end to end storage performance. As soon as virtual machines stored on a Scale-Out File Server are started, their performance is monitored. Performance details of all running virtual machines and the configuration of the Scale-Out File Server cluster can be viewed from a single location
  • Manage Storage I/O per workload business needs Storage QoS policies define performance minimums and maximums for virtual machines and ensures that they are met. This provides consistent performance to virtual machines, even in dense and overprovisioned environments. If policies cannot be met, alerts are available to track when VMs are out of policy or have invalid policies assigned.

Storage QOS & Networking

What’s New in Networking with S2D?

In Windows Server 2016, they added Remote Direct Memory Access (RDMA) support to the Hyper-V virtual switch.

For those that don’t know what RMDA is it technology that allows direct memory access from one computer to another, bypassing TCP layer, CPU , OS layer and driver layer. Allowing for low latency and high-throughput connections. This is done with hardware transport offloads on network adapters that support RDMA.

Back to Hyper-V virtual switch support for RDMA.  This allows you to configure regular or RDMA enabled vNICs on top of a pair of RDMA capable physical NICs. They also added embedded NIC teaming or Switch Embedded Teaming (SET).

SET is where NIC teaming and the Hyper-V switch is a single entity and can now be used in conjunction with RDMA NICs, wherein Windows 2012 Server you needed to have separate NIC teams for RDMA and Hyper-V Switch.

The images below illustrates the architecture changes between Windows Server 2012 R2 and Windows Server 2016.

Storage QOS & Networking

Storage QOS & Networking

Next up…Management and Operations, Until next time, Rob


NPP Training series – How does it work – CVM – Software Defined

To continue NPP training series here is my next topic:  How does it work – CVM – Software Defined

If you missed other parts of my series, check out links below:
Part 1 – NPP Training series – Nutanix Terminology
Part 2 – NPP Training series – Nutanix Terminology
Cluster Architecture with Hyper-V

Data Structure on Nutanix with Hyper-V
I/O Path Overview
Drive Breakdown

To give credit, most of the content was taken from Steve Poitras’s “Nutanix Bible” blog as his content is the most accurate and then I put a Hyper-V lean to it. Also, he just rocks…other than being a Sea Hawks Fan :).

Nutanix CVM

As mentioned before (likely numerous times), the Nutanix platform is a software-based solution which ships as a bundled software + hardware appliance.  The controller VM or what we call the Nutanix CVM is where the vast majority of the Nutanix software and logic sits and was designed from the beginning to be an extensible and pluggable architecture. A key benefit to being software-defined and not relying upon any hardware offloads or constructs is around extensibility.  As with any product life cycle, advancements and new features will always be introduced.

By not relying on any custom ASIC/FPGA or hardware capabilities, Nutanix can develop and deploy these new features through a simple software update.  This means that the deployment of a new feature (e.g., deduplication) can be deployed by upgrading the current version of the Nutanix software.  This also allows newer generation features to be deployed on legacy hardware models. For example, say you’re running a workload running an older version of Nutanix software on a prior generation hardware platform (e.g., 2400).  The running software version doesn’t provide deduplication capabilities which your workload could benefit greatly from.  To get these features, you perform a rolling upgrade of the Nutanix software version while the workload is running, and you now have deduplication.  It’s really that easy.

Similar to features, the ability to create new “adapters” or interfaces into Distributed Storage Fabric is another key capability.  When the product first shipped, it solely supported iSCSI for I/O from the hypervisor, this has now grown to include NFS and SMB for Hyper-V.  In the future, there is the ability to create new adapters for various workloads and hypervisors (HDFS, etc.).  And again, all of this can be deployed via a software update. This is contrary to most legacy infrastructures, where a hardware upgrade or software purchase is normally required to get the “latest and greatest” features.  With Nutanix, it’s different. Since all features are deployed in software, they can run on any hardware platform, any hypervisor, and be deployed through simple software upgrades.

The following figure shows a logical representation of what this software-defined controller framework (Nutanix CVM) looks like:Nutanix CVMNext up, NPP Training Series – How does it all work – Disk Balancing