I don't know how Starwind vSAN can be run but if it's on a hypervisor it's severely limited by I/O congestion through the kernel. NVMe drives is causing problems that was of no concern whatsoever with spinners. Both KVM and Xen has made a lot of work to limit their I/O latency and use polling techniques now but it's still a problem. That's why you really need SR-IOV on NVMe drives so any VM can bypass the hypervisor and just have it's own kernel to slow things down.

Anton: There are no problems with polling these days You normally spawn a SPDK-enabled VM (Linux is unbeatable here as most of the new gen I/O development happens there) and pass thru RDMA-capable network hardware (virtual function with SR-IOV or whole card with PCIe pass-thru, this is really irrelevant...) and NMVe drives and... magic starts happening This is how our NVMe-oF target works on ESXi & Hyper-V (KVM & Xen have no benefits here architecturally, this is where you're either wrong or I failed to get your arguments). It's possible to port SPDK into Windows user-mode but lack of NVMe and NIC polling drivers takes away all the fun: to move the same amount of data we normally use ~4x more CPU horsepower on "Pure Windows" Vs. "Linux-SPDK-VM-on-Windows" models. Microsoft is trying to bring SPDK to Windows kernel (so does VMware from what I know), but it needs a lot of work from NIC and NVMe engineers and... nobody wants to contribute. Really.

Just my $0.02

@pmoncho said in I think I am missing something about Hyper-V....?:

@kooler said in I think I am missing something about Hyper-V....?:

In general we shift our focus from "Hyper-V and VMware" to "VMware and KVM". Reason: Hyper-V doesn't grow anymore and KVM has very high chances to supersede it. VMware... There's just more money there

Could you expand on your statement about Hyper-V not growing? Thanks

% between VMware, ESXi and KVM for acquired number of customers doesn't look good for Microsoft.

@stacksofplates said in I think I am missing something about Hyper-V....?:

@scottalanmiller said in I think I am missing something about Hyper-V....?:

@bnrstnr said in I think I am missing something about Hyper-V....?:

@scottalanmiller said in I think I am missing something about Hyper-V....?:

@bnrstnr said in I think I am missing something about Hyper-V....?:

My opinion is Hyper-V is only an option when you need vSAN, otherwise I’m just not buying it.

What makes it special in that case? AFAIK there is no production vSAN for Hyper-V that is unique to it. Hyper-V is effectively completely dependent on Starwind for vSAN and they recommend KVM most of the time.

Right, Starwind makes it a more viable solution because it’s free and easy and well documented, right?

No, Starwind does not. Starwind just doesn't discriminate against it. Starwind is just as easy on VMware or KVM. So it's a draw, unless you consider Xen, then it is just a negative for Xen.

Eh not really. They dropped support for the virtual appliance on anything other than VMware. So you have to manually do the work on KVM/Hyper-V or just aren't able to do it at all. I can't tell.

This one will be back soon. We'll have a GA for VMware VSA around next week and KVM will follow.

In general we shift our focus from "Hyper-V and VMware" to "VMware and KVM". Reason: Hyper-V doesn't grow anymore and KVM has very high chances to supersede it. VMware... There's just more money there

@scottalanmiller said in Hyper-V replication, Starwind, or something else?:

@doyler3000 said in Hyper-V replication, Starwind, or something else?:

Oh and I've already got Veeam backup and replication (a 30 vm license) which gives me good agentless backup options for Hyper-V. 5-nine manager or something like it would likely be required as well.

5-Nine would be "extra" stuff only needed because Hyper-V doesn't have the native options that it provides. Another reason for KVM.

Veeam is great, but they have agent based for your scenario. We have another thread right now talking about this, but why do you see agentless as even something you want, let alone a driving factor in decision making? It sounds nice, but is very rarely (especially in such a large, diverse shop) viable.

Well, Microsoft released WAC (Windows Admin Center, ex- "Project Honolulu") to fill lack of management gap, but... I'm very pessimistic about WAC so far: too many compatibility issues and no single scenario is covered from Day Zero till the very end. Bottom line: You'll have to learn PowerShell and Windows Server management cmdlets.

@scottalanmiller said in Hyper-V replication, Starwind, or something else?:

@doyler3000 said in Hyper-V replication, Starwind, or something else?:

Out of roughly 30 VMs, 2 are Windows server instances. We're mostly running Centos here.
I'll look into SA licensing. I'm not very familiar with it.

Given that skill set, why look at Hyper-V instead of KVM? Both have been officially dropped from Starwind support temporarily until their new product roles out, which is KVM first, that's their key focus as they see it as the one with the greater future and potential. Hyper-V in general is more complex to manage than KVM. It's a fine product, but given your skill set and existing products, KVM seems like a more natural fit. Generally, Hyper-V makes sense only when you require a specific feature of it.

I'd tend to agree here, KVM running Linux VMs sounds like a better choice. Hyper-V makes sense if it's a "free" offering comping as part of already paid Windows Server licenses.

P.S. Not sure about VM backup with KVM.

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

Hi,

I have server with 2 x 1 TB SSD and 2 x 2 TB SATA.

I want to use this server as VM host.
My questions are :

1. Can I do RAID 1 for each SSD and SATA?
2. Can Raid 10 do different size and model (1TB SSD & 2TB SATA)?
3. What is the best RAID configuration for above use?
4. Should I go hardware RAID? or MDADM? I heard hardware is slower for SSD RAID?
5. What filesystem I should use on the host? ext4 or LVM? or other?
6. If I use CentOS 7, do you recommend XEN / VM for stability and user friendly system?

My aim is to get full speed with SSD for critical VM (database server VM guest, web apps, etc) and less critical VM on sata (mail server VM guest, etc).

Thank you.

Don't mix different types of the drives with different performance inside the same pool: you'll limit your resulting performance with the slowest (in your content - HDD).

@r3dpand4 said in Configuring Multi-Resilient Volume with Storage Spaces:

Should be noted that any server running 1709 cannot be added to S2D pools as it stands currently since it's not considered production ready....

Correct. S2D is gone from non-GA WS2016.

https://docs.microsoft.com/en-us/windows-server/get-started/server-1709-relnotes

Storage Spaces Direct

Storage Spaces Direct is not included in Windows Server, version 1709. If you call Enable-ClusterStorageSpacesDirect or its alias Enable-ClusterS2D, on a server running Windows Server, version 1709, you will receive an error with the message "The requested operation is not supported". It is also not supported to introduce servers running Windows Server, version 1709 into a Windows Server 2016 Storage Spaces Direct deployment.

@momurda said in Microsoft Removes Storage Spaces Direct from Windows Server 2016:

You will have to buy Windows Super Server Edition 2016 to get this functionality. At twice the price.
Seriously, that blurb says that MS is 'thrilled' about adoption of Storage Spaces Direct

"Storage Spaces Direct was introduced in Windows Server 2016 and is the foundation for our hyper-converged platform. We have been thrilled by the positive adoption of the Microsoft hyper-converged platform and we are committed to our customers."

so why take it away?

Don't listen to anything people say, watch what they DO.