Windows Storage Spaces

[orangeTANG]

Are there any limitations using Windows Storage Spaces inside a Windows 2019 Guest VM? Considering using storage spaces instead of Dynamic Striped Disks to use 2 vDISKs to make 1 logical drive (for performance reasons). Some Google searches suggest that Veeam can only do full drive restores, and not single file restores out of Storage Space volumes but these posts are a few years old.

I just like to know if there's any limitations from the Veeam backup side (specifically AHV) before we decide to follow Storage Spaces instead of Striping per MS current best practice.

[Andreas Neufert]

It is not supported by Microsoft to use storage spaces in VMs and therefore our VM file restore and applications do not support it.

[orangeTANG]

Andreas - thank you for the response. I did see references to that but they were quite old, I was unsure if that was still the case. I did set up a test in my lab and I can confirm that Veeam does not see the volume created in Storage Spaces to do file level restores.

What is odd is I see MS articles suggesting the use of Dynamic Striped disks are depreciated, and 3rd party references to Nutanix shift to Storage Spaces for vDisks: https://www.derekseaman.com/2019/02/win ... tanix.html

I do have a ticket open with Nutanix to understand their best practice, but regardless I cannot go that route since Veeam doesn't support it.

[Andreas Neufert]

I checked with latest Microsoft documentation and for "Storage Spaces" I did not find any new documentation that it would be supported within VMs. It has still a strict requirement for Storage Controllers one HCL.
Maybe a Microsoft Advisory case can bring some light into it.

However I saw some "Storage Spaces Direct" on Azure documentation, but it speaks about Multi Server distributions which do not allow us to backup and restore them on image level.

However if you have specific data within Storage Spaces or Storage Spaces direct and you want to backup those on file backup level, you can use our NAS backup solution (Backup SMB share).

[NezzerGetti]

Hey! Bumping this thread. How are things looking in 2025?

Looking at Microsoft howtos they are actually using virtual disks inside a standalone setup in a VM. https://learn.microsoft.com/en-us/shows/oemtv/oem1631
There is also a bunch of Azure related howtos talking about virtual storage spaces deployment.

Makes me confused about what's supported or not.
It's a shame that FLR does not have support for storage spaces in my opinion.

So why would one even want storage spaces inside a VM?
First i would say it's due to spanned drives are deprecated.
Secondly I would say that it's vital since hotadd does not support over 2TB drives. Which in a file share setup is not enough.

Workarounds like NAS storage and Agents are effectively doubbling the amount of backup storage needed since you need to snapshot the full machine anyway if you want a fast recovery operation of the full vm.

Am I missing something or what is the recommended approach to backup a large VM that needs to have multiple vmdks? Well that is except from having to move around data and recreate shares when any vmdk closes in on the 2tb mark?

[david.domask]

Hi Andreas,

The situation has not changed, Storage Spaces still is not supported.

Can I ask, what is the datastore type and vsphere version in play? You mentioned 2TB limit for drives, but but for vSphere 5.5 and later 62 TiB is the maximum allowed size.

Instant Recovery likely will be the best option here for recovery with the current setup and Storage Spaces, but I guess I wonder if the 2 TiB limit is real for you as VMFS-5 supports larger VMDKs, so is Storage Spaces even needed? Or do you have older vSphere versions in the environment prevent this for you?

[NezzerGetti]

Hello!

Okay, that is a shame. I guess the only viable option for me would be to perform both vmbackup and NAS backup on the same VM to get fast access to FLR restores. Instant recovery as FLR is not an option for non veeam baptized staff.

Datastore is VMFS for Version 8. But will be changed to proxmox solution later on.

I'm actually not refering to the VMFS limits at all since they are as you say very much higher. I'm refering to recommended setups regarding hotadd. Could not find any official docs regarding this but here is a forum post: vmware-vsphere-f24/max-virtual-disk-siz ... 14697.html I've been using Veeam since V 5.5 and I've always been told by support to use maximum 2TB VMDK's for vm's backed by hotadd, Has this changed ?

[david.domask]

Aha, if you check the links I provided, it outlines how vSphere 5.5 and VMFS-5 changed the landscape for that quite a bit by increasing the allowed VMDK size. You can see the posts you're referring to are from 2012 or older and talk about VMFS-3 limitations You can see even Vmware's own programming guide (page 28) the same guidance for hotadd proxy sizing, and it only concerns itself if the proxy is on a VMFS-3 datastore.

So while I understand the problem you're trying to address at the moment, the 2 TB limitation has not been relevant for some years as VMware allows larger VMDKs now, and this works fine with hotadd. Basically, I'm just not sure I see the need for Storage Spaces for VMs at the moment as this just isn't an issue with most of the hypervisors anymore, so I would revisit the idea of Storage Spaces personally, as I think you don't need to consider it and this solves a lot of the concerns on recovery operations

[NezzerGetti]

Hello again.

Seems like I've missed some tech then.
However regarding performance. Are the limitations still max 1Gbit per VMDK in Veeam ?

EG lets pretend that I create a 10TB VMDK and make a fileshare on it. Wouldn't that take ages to backup since I then only read all that data from one snapshot?
Dividing VMDK's makes for excellent parallell performance.

[david.domask]

Hi Andreas,

Yeah, I can remember the times when your information was correct, but indeed things have advanced a bit since vsphere 5.5.

Since we're getting into discussion that is offtopic from the original question, I'll link to our FAQ on transport modes and architecture for vSphere, as this is current as of Veeam 12.3 (the FAQ says 12.1, but the VMware section has not changed for 12.3) I think it would help with an overview on the current state of vmware backups.

Start with that and if there are further questions from that, please create a new topic on our vSphere forum.

> Dividing VMDK's makes for excellent parallell performance.

You are correct on this It is both true that larger VMDKs solves the storage spaces issue, but also requires consideration on the backup process. I think first give the FAQ a read through, and let's continue in the proposed new topic as we're getting into Vmware design strategies now.

[NezzerGetti]

Hello David.

Yes we are indeed getting out of topic now. And I'm feeling a bit like a fossil now.
I will try to create a single VMDK and run a hotadd backup to see if it matches the performance of the storage and do a bit of reading.

Thank you!