DELL Microsoft Storage Spaces Offerings

Dell was the 1st OEM to actively support and deliver Microsoft Storage Spaces solutions to its customers.


They recognized the changing landscape of storage and saw that this was one of the option customers are interested in. When DELL adds their logistical prowess and support infrastructure into the equation it helps deliver Storage Spaces to more customers. It removes barriers.

In June 2015 DELL launched their newest offering based on generation 13 hardware.


Recently DELL has published it’s docs and manuals for Storage Spaces with the MD1420 JBOD Storage Spaces with the MD1420 JBOD

You can find some more information on DELL storage spaces here and here.

I’m looking forward to what they’ll offer in 2016 in regards to Storage Spaces Direct (S2D) and networking (10/25/40/50/100Gbps). I’m expecting that to be a results of some years experience combined with the most recent networking stack and storage components. 12gbps SAS controller, NVMe options in Storage Spaces Direct. Dell has the economies of scale & knowledge to be one of the best an major players in this area. Let’s hope they leverage this to all our advantage. They could (and should) be the first to market with the most recent & most modern hardware to make these solutions shine when Windows Server 2016 RTM somewhere next year.

Hyper-V Storage QoS in Windows Server 2016 Works on SOFS and on LUNs/CSVs


I addressed storage QoS in Windows Server 2012 R2 at length in a coupe of blog posts quite a while ago:

I love the capability and I use it in real life. I also discussed where we were still lacking features and capabilities. I address the fact that there is no multiple host QoS, there is no cluster wide QoS and there is no storage wide QoS in Windows. On top of that, if there is QoS in the storage array (not many have that) most of the time this has no knowledge of Hyper-V, the cluster and the virtual machines. There is one well know exception and that GridStore, possible the only storage vendor that doesn’t treat Hyper-V as a second class citizen.

Any decent storage QoS that not only provides maximums but also minimums, does this via policies and is cluster and hypervisor even virtual machine aware. It needs to be easy to implement and mange. This is not a very common feature. And if it’s exists it’s is tied to the storage vendor, most of the time a startup or challenger.

Windows Server 2016

In Windows Server 2016 they are taking a giant step for all mankind in addressing these issues. At least in my humble opinion. You can read more here:

Basically  Microsoft enables us to define IOPs management policies for virtual machines based on virtual hard disks and  IOPs reserves and limits. These are shared by a group of virtual machines / virtual hard disks.  We can have better resource allocation between VMs, or groups of VMs. These could be high priority VMs or VMs belonging to an platinum customer /tenant. Storage QoS enhances what we already have since Windows Server 2012 R2.  It enables us to monitor and enforce performance thresholds via policies on groups of VMs or individual VMs.

Great for SLA’s but also to make sure a run away VM that’s doing way to much IO doesn’t negatively impact the other VMs and customers on the cluster. They did this via via a Centralized Policy Controller. Microsoft Research really delivered here I would dare say. A a public cloud provider they must have invested a lot in this capability.

At Ignite 2015 there was a great session by Senthil Rajaram and Jose Barreto on this subject. Watch it for some more details.

What caught my eye after  attending and watching sessions, talking to MSFT at the boot was the following marked in red.


So not enabled by default on non SOFS storage but can you enable it on your block level CSV Hyper-V cluster? There is a lot of focus on Microsoft providing Storage QoS for SOFS. Which ties into the “common knowledge” that virtualization and LUNs are a bad idea, you need file share and insights into the files of the virtual machines to put intelligence into the hypervisor or storage system right? Well perhaps no! I Windows Server 2016 there is now also the ability to provide it to any block level storage you use for Hyper-V. Yes your low end iSCSI SAN or your high End 16Gbps FC SAN … as long as it’s leveraging CVS (and you should!). Yes, this is what they state in an awesome interview with my Fellow Hyper-V MVP Carsten Rachfahl at Ignite 2015.

Videointerview with Jose and Senthil Storage QoS Thumb2

Senthil and Jose look happy and proud. They should be.  I’m happy and proud of them actually as to me this is huge. This information is also in the TechNet guide Storage Quality of Service in Windows Server Technical Preview

Storage QoS supports two deployment scenarios:

Hyper-V using a Scale-Out File Server This scenario requires both of the following:

  • Storage cluster that is a Scale-Out File Server clusterCompute cluster that has least one server with the Hyper-V role enabled.
  • For Storage QoS, the Failover Cluster is required on Storage, but optional on Compute. All servers (used for both Storage and Compute) must be running Windows Server Technical Preview.

Hyper-V using Cluster Shared Volumes. This scenario requires both of the following:

  • Compute cluster with the Hyper-V role enabled
  • Hyper-V using Cluster Shared Volumes (CSV) for storage

Failover Cluster is required. All servers must be running Windows Server Technical Preview.

So let’s have a quick go following the TechNet guide on a lab cluster leveraging CSV over FC with a Dell Compellent.image

Which give me running Storage QoS Resource


And I can play with my new PoSh Commands … Get-StorageFlowQos, Get-StorageQosPolicy and Get-StorageQosVolume …


The guide is full of commands, examples and tips. Go play with it. It’s great stuff Smile. I’ll blog more as I experiment.

Here’s my test VMs doing absolutely nothing, bar one on which I’m generating traffic. Even without a policy set it shows the IOPS the VM is responsible for on the storage node.image

Yu can dive into this command and get details about what virtual disk on what volume are contributing to the this per storage node.


More later no doubt but here I just wanted to share this as to me this is very important! You can have the cookie of your choice and eat it to! So the storage can be:

  1. SOFS provided (with PCI RAID, Shared SAS, FC, FCoE, ISCI storage as backend storage) that doesn’t matter. In this case Hyper-V nodes can be clustered or stand alone
  2. The storage can be any other block level storage: iSCSI/FC/FCoE it doesn’t matter as long as you use CSVs. So yes this is clustered only. That Storage QoS Resource has to run somewhere.

You know that saying that you can’t do storage QoS on a LUN as they can’t be tweaked to the individual VM and virtual hard disks? Well, that’s been busted as myth it seems.

What’s left? Well if you have SOFS against a SAN or block level storage you cannot know if the storage is being used for other workloads that are not Hyper-V, policies are not cross cluster and stand alone hosts are a no go without SOFS. The cluster is a requirement for this to work with non SOFS Hyper-V deployments.  Also this has no deep knowledge or what’s happening inside of your storage array. So it knows how much IOPS you get, but it’s actually unaware of the total IOPS capability of the entire storage system or controller congestion etc. Is that a big show stopper? No. The focus here is on QoS for virtualization. The storage arrays storage behavior is always in flux anyway. It’s unpredictable by nature. Storage QoS is dynamic and it looks pretty darn promising to me! People this is just great. Really great and it’s very unique as far as I can say. Microsoft, you guys rock.

Hyper-V Virtual Machines and the Storage Optimizer

Windows Server 2012 (R2) has made many improvements to how storage optimization and maintenance is done. You can read a lot more about this in What’s New in Defrag for Windows Server 2012/2012R2. It boils down to a more intelligent approach depending on the capability of the underlying storage.

This is reflected in the Media type we see when we look at Optimize Drives.

This is my workstation … looks pretty correct a couple of SSDs and a couple of HDDs.


SSD are optimized intelligently by the way.When VSS is leveraged SSD do get fragmentation and so one in while they are “defragmented”. This has to do with keeping performance up to par. Read more about this in The real and complete story – Does Windows defragment your SSD? by Scott Hanselman.

The next example is a Hyper-V Cluster. You can see the local disks identified as HDD and the CSV as Thin provisioned disks. Makes sense to me, the SAN I use supports thin provisioned disks.


But now, let’s look at a Virtual Machine with virtual disks of every type known and on any type of storage we could find. All virtual disks are identified as “Thin provisioned disk”. How can that be?


What had me puzzled a little bit is that in a virtual machine each and every virtual disk is identified as thin provisioned disk. It doesn’t matter what type of virtual disk it is: fixed VHD/VHDX or dynamically expanding VHD/VHDX. It also doesn’t matter on what physical disk the virtual disk resides: SATA, SAS, SSD, SAN (iSCSI/FC) LUN or CSV, SMB Share …

So how does this work with a fixed VHD on a local SATA disk? A VHD doesn’t know about UNMAP, does it? And a SATA HHD? How does that compute? Well, my understanding on this is that all virtual disks, dynamically expanding or fixed, both VHDX/VHD are identified as thin provisioned disks, no matter what type of physical disk they reside on (CSV, SAS, SATA, SSD, shared/non shared). This is to allow for UNMAP (RETRIMs in Storage Optimizer speak, which is  way of dealing with the TRIM limitations / imperfections, again see Scott Hanselman’s blog for this) command to be sent from the guest to the Hyper-V storage stack below. If it’s a VHD those UNMAP command are basically black holed just like they would never be passed down to a local SATA HHD (on the host) that has no idea what it is and used for.

But wait a minute ….what about SSD and defragmentation you say, my VHDX lives on an SSD.. Well they are for one not identified as SSD or HDD. The hypervisors deals with the storage optimization at the virtual layer. The host OS handles the physical layer as intelligent as it can to optimize the disks as best as it can. How that happens depends on the actual storage beneath in the case of a modern SAN you’ll notice it’s also identified as a Thin provisioned disk. SANs or hyper converged storage arrays provide you with storage that is also virtual with all kinds of features and are often based on tier storage which will be a mix of SSD/SAS/NL-SAS and in some cases even NVMe Flash. So what would an OS have to identify it as?  The storage array must play its part in this.

So, if you ever wondered why that is, now you know. Hope you found this interesting!

E2EVC 2015 Berlin SMB Direct Slide Deck

I attended and presented at E2EVC 2015 in Berlin from June 12th to June 14th. The networking was a blast. No “marchitecure” bull shit or vendor fairy tales what so ever and lots of very open discussions on the realities we’re seeing and facing in virtualization and cloud. Most account managers and esoteric presales would die a painful (but fast) death in this environment.


One session was with my Hyper-V Amigo buddy Carsten Rachfahl and was pure demo extravaganza, so no slides. My own session was “SMB Direct – The Secret Decoder Ring” and was an attempt to position this technology what by looking at the why and where followed by the how by who and when.


I hope a lot of people had at least a better understanding of SMB Direct, RDMA and DCB. The second aim was to take away the fear many people have of this tech by showcasing it in short demos. Time constraints where a challenge so it was not a 200 level session.

Please download the presentation here if interested.

Enjoy. If you have any concerns or questions, ask, and I’ll try to answer.