Category Archives: IT Pro

The Hyper V Amigos Showcast Episode 6: Storage Spaces

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Everybody is very busy and I’m a bit tires but here’s the 6th episode of the Hyper-V Amigos show cast. In this episode we get to play a bit with storage spaces in Carsten’s lab.

As always we had a lot of fun doing so and thanks to Carsten Rachfahl and the assistance of Kerstin (his charming wife, also an MVP, in Office 365) we could simulate hardware failures & film them for you!

 

Carsten & I discuss several scenarios and what’s happening during failovers. Carsten is assisting customers with this a lot so he has some of the most varied experience with storage spaces and SOFS out there!  Interesting stuff and for people who haven’t even looked at Windows Server 2012 or later yet a wake up call to start as the world is not limited to what we once knew. It’s not your daddy’s Windows anymore Winking smile

I hope you enjoy it and we’re already planning for the next one!

Microsoft Keeps Investing In Storage Big Time

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Disclaimer: These are my musing on the limited info available about Windows Server vNext and based on the Technical Preview bits at the time of writing. So it’s not set in stone & has a time limited value.

Reading the documentation that’s already available on vNext of Windows it’s clear that Microsoft is continuing it’s push towards the software defined data center. They are also pushing high to continuous availability ever more towards the  “continuous” side of things.

It’s early days yet and we just only downloaded the Technical Preview but what do we read in What’s New in Storage Services in Windows Server Technical Preview

Storage Quality of Service

  • They are giving us more Storage Quality of Service tied into the use of SOFS as storage over SMB3. As way to many NAS solutions don’t support SMB3 or only partially (in a restricted way) it’s clear too me that self build SOFS solution on a couple of servers is and remains the best SMB3 implementation on the market and has just gotten storage QoS.

Little Rant here: To the people that claim that this is not capable of high performance, I usually laugh. Have you actually build a SOFS or TFFS with 10Gbps networking on modern enterprise grade servers line the DELL R720 or 730? Did you look at the results form that relative low cost investment? I think not, really. And if you did and found it lacking, I’ll be very impressed of the workload you’re running.  You’ll force your storage to the knees earlier than your Windows file server nowadays.

  • It’s in the SOFS layer, so this does not tie you into to Storage Space if you’re not ready for that yet but would like the benefits of SOFS. As long as you have shared storage behind the SOFS you’re good.
  • It’s policy based and can apply to virtual machines, groups of virtual machines a service or a tenant
  • The virtual disk is the level where the policy is set & enforced.
  • Storage performance will dynamically adjust to meet the policies & when tied the performance will be fairly distributed.
  • You can monitor all this.

It’s right there in the OS.

Storage Replica

This gives us “storage-agnostic, block-level, synchronous replication between servers for disaster recovery, as well as stretching of a failover cluster for high availability. Synchronous replication enables mirroring of data in physical sites with crash-consistent volumes ensuring zero data loss at the file system level. Asynchronous replication allows site extension beyond metropolitan ranges with the possibility of data loss.”

Look for Hyper-V we already had Hyper-V replica (which is also being improved), but for other workloads we still rely on the storage vendors or 3rd party solutions. But now I can have my storage replicas for service protection and continuity out of the box with Windows.  WOW!

and as we read on ..

  • Provide an all-Microsoft disaster recovery solution for planned and unplanned outages of mission-critical workloads.
  • Use SMB3 transport with proven reliability, scalability, and performance.
  • Stretch clusters to metropolitan distances.
    Use Microsoft software end to end for storage and clustering, such as Hyper-V, Storage Replica, Storage Spaces, Cluster, Scale-Out File Server, SMB3, Deduplication, and ReFS/NTFS.
  • Help reduce cost and complexity as follows:

Hardware agnostic, with no requirement to immediately abandon legacy storage such as SANs.

Allows commodity storage and networking technologies.
Features ease of graphical management for individual nodes and clusters through Failover Cluster Manager and Microsoft Azure Site Recovery.

Includes comprehensive, large-scale scripting options through Windows PowerShell.

  • Helps reduce downtime, and increase reliability and productivity intrinsic to Windows.
  • Provide supportability, performance metrics, and diagnostic capabilities.

I have gotten this to work in the lab with some trial and error but this is the Technical Preview, not a finish product. If they continue along this path I’m pretty confident we’ll have functional & operational viable solution by RTM. Just think about the possibilities this brings!

Storage Spaces

Now I have not read much on Storage Space in vNext yet but I think its safe to assume we’ll see major improvements there as well. Which leads me to reaffirm my blog posy here: TechEd 2013 Revelations for Storage Vendors as the Future of Storage lies With Windows 2012 R2

Microsoft is delivering more & great software defined storage inbox. This means cost effective yet very functional storage solutions. On top of that they put pressure on the market to deliver more value if they want to stay competitive. As a customer, whatever solution fits my needs the best, I welcome that. And as a consumer of large amounts of storage in a world where we need to spend the money where it matters most I like what I’m seeing.

Tip for Microsoft: configurability, reliability and EASY diagnostics and remediation are paramount to success. Sure some storage vendor solution aren’t to great on that front either but some are awesome. Make sure your in the awesome category. Make it a great user experience from start to finish in both deployment and operations.

Tip for you: If you’re not ready for prime time with Storage Spaces , SMB Direct etc … do what I’ve done. Use it where it doesn’t kill you if you hit some learning curves. What about storage spaces as a backup target where you can now replicate the backups of to your disaster recovery site?

Hot Add & Remove Static Memory in a Hyper-V vNext Virtual Machine

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One of the very nice and handy new capabilities in Windows Server vNext Hyper-V (Windows Server 2015 or Windows Server 10?) is the fact that you can now hot add or remove memory from a virtual machine with a fixed amount of memory. Another step towards continuous availability.

Here’s a test virtual machine RAGNAR running the Technology Preview bits on my test cluster. As you can see it has 1024MB of fixed memory. And Dynamic memory is not enabled.

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I can simply adjust this upward by typing in the value and clicking “Apply”

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and downwards in the same way

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Cool huh!

On top of this to make sure you’re not adding memory needlessly when someone says they need more memory for their VM you can see the memory demand now in the GUI. Both in Hyper-V Manager and in the Failover Clustering GUI.

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The technical preview of Windows vNext is looking good even in this early stage and I have no doubt it’s only going to get better Open-mouthed smile.

Some things to note

  • It’s configurable via PowerShell so you can start dreaming of script to query memory assignment & demand and use that output to redistribute memory available on the host amongst the VMs …

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  • Both Hyper-V host and guest have to run vNext (Technical Preview)
  • The guest has to be a generation 2 VM
  • It’s still virtualization technology and not magic, so if you try to assign more memory than available you’ll get a warning Winking smile

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Windows Server 2012 R2 Clustering brings improved CSV diagnosability

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Cluster Shared Volumes (CSV) have can go into different redirected access modes for several reasons. Now a lot of people get (or got) worried about seeing “redirected access” in the GUI. Most of the time however this is due to normal operations such as backups or maintenance (defragmentation) not only losing disk access.

To remediate unneeded troubleshooting, sometimes leading to real issues, calls to MSFT support and so forth it was hidden from the Failover Clustering GUI in Windows 2012 R2. OK, so goal achieved but how do we now troubleshoot and view redirected access that might indicate the presence of real issues? The answer to that is the Get-ClusterSharedVolumeState PowerShell cmdlet. It displays the state of the CSVs on a per node basis for a cluster. You’ll see the type of the IO (Direct, File System Redirected and Block Redirected), if it’s completely unavailable  as well as the reason.

This is what the output looks like on a two node cluster where node A has lost it’s storage path or paths (MPIO) to the CSV. You’ll see that both CSV are in redirected access. Not only that but you can see what type (block redirected) and why (no disk connectivity).

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Pretty neat and clear. I love this functionality by the way and It’s why I’m leveraging 10Gbps Ethernet extensively to make sure that CSV traffic get’s the bandwidth & latency to handle what it has to. If you realize it leverages SMB3 which provides SMB Multichannel and SMB Direct you know it will get the job done for you in your time of need.

While this is happening in the GUI you’ll see this

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Nothing is going on … it would seem so a bit of monitoring and alerting would be of use here. The good news is finding out what’s up is very straight forward now.

Now there is still a case where you’ll see that the CSV is in redirected access mode and that when you’ve put it in there yourself via the GUI

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or via PowerShell for maintenance reasons.

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As you can see the Icon has change to a networked disk one and it states “Redirected Access”. With Get-ClusterSharedVolumeState the output looks like this.

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You’ll always see warnings in the event logs.

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So monitor those with SCOM or another tool that suits your taste and you’ll be in good shape to react when it’s needed and you now know how to find out what’s going on.