Windows Server 2019 DataCenter: adding disks to the Storage Pool (with mirror accelerated parity) doesn't increase storage space?

(old title: Storage Spaces on stand-alone Windows Server 2019 Datacenter: what are my options with 2x SSD and 4x HDD?)

I have 2x 1.75TB SSD + 4x 3.64TB HDD. I thought to use Storage Tier but I am unable to create a Virtual Disk for my Data Storage Pool.

I've been playing around for some time now (https://docs.microsoft.com/en-us/answers/questions/275652/2x-175tb-ssd-4x-4tb-hdd-but-creating-a-volume-give.html?childToView=277348#answer-277348 - The storage pool does not have sufficient eligible resources for the creation of the specified virtual disk) and I'm unable to get anything created*

So clearly I'm overlooking something very obvious. Therefore my question for the ppl with hand-on experience: what should I be able to do with these 6 disks (when needed, I can add a 5th 3.64TB HDD)?

I like the idea of Storage Tiers (hot data on SSDs, cold data moved to HDDs) and I really need to be able to survive 1 or even 2 disk crashes without losing any data.

What's wisdom here pretty please? :) Am I fighting with a bug or with my own lack of knowledge?

Appreciated!

*2 exceptions, but I don't know wtf I ended up with; nor did the numbers make any sense to me. https://docs.microsoft.com/answers/comments/275805/view.html

POST-EDIT 01: I can add a 5th HDD right now (but I'd prefer not to) and in total I could have 8 bays in use (though I'd like to reserve 1 bay for a big ass HDD)

POST-EDIT 02: while the step-by-step seems to fail, I did get it working. But the results are weird to me.

These are the commands I am testing with ("OpslagBad is the Storage Pool I created with the GUI):

New-StorageTier -StoragePoolFriendlyName OpslagBad -FriendlyName performance -MediaType SSD

New-StorageTier -StoragePoolFriendlyName OpslagBad -ResiliencySettingName Parity -FriendlyName capacity -MediaType HDD

New-Volume -FriendlyName 2SSD4HDD -FileSystem ReFS -StoragePoolFriendlyName OpslagBad -StorageTierFriendlyNames performance, capacity -StorageTierSizes 1.7TB, 3.6TB

My disks are 1.75TB and 3.64TB but if I enter those sizes, New-Volume fails.

Now for the experimenting part :( 1x SSD + 1x HDD fail for New-Volume. As it does for 1x SSD + 2x HDD and 2x SSD + 2x HDD. I'm willing to accept that without knowing why :)

With 2x SSD and 3x HDD I do end up with a volume. Its size is 5.30TB. With 3x 3.6TB + 2x 1.7TB (= 10.8TB + 3.4TB = 14.2TB of disks). That's a big hit but could make sense - the fewer the amount of disks, the worse the impact of parity. I should be happy now. But I have more disks, so let's go on and increase efficiency.

So I add a 4th HDD to the Storage Pool and repeat the PS commands (after removing the current virtual disk). I AGAIN end up with a 5.3 TB virtual disk... wtf? what happened to all that extra disk space? What is Windows doing here? Can I control this somehow? Storage efficiency should go up, not get less, with more disks!

So I try with a 5th HDD disk added (so 2x SSD + 5x HDD). AGAIN I only have a 5.3TB virtual disk (5.25TB free). What happened to those 2x HDDs I added?? Why isn't my storage space increasing? :(

I’d suggest you to stick with so-called mirror accelerated parity. It’s not supported officially for non-OEMs, but it works just fine for many scenarios. You’ll get best disk usage with it and you’ll able to survive double disk faults. Here’s a good guide on that.

http://knowledgebase.45drives.com/kb/kb450193-creating-mirror-accelerated-parity-volumes-and-storage-tiers-in-storage-spaces-windows-server-2019/

As Fate would have it I have been having similar problems with 8 disk's 4 SSD and 4 HDD. I like you am inexperienced with windows and am eager to learn. I too have scoured the internet using google and have so many bookmarked pages it is almost overwhelming.

It is nice to know it not just me who have had these same errors and same frustrations! Thanks for taking the time to map out what you have done and tried to do.

Mine had a slight twist in that I wanted to run a VM in Hyper-V using Storage Tiers passed from the core host to the VM file server. I finale got it using Powershell with the help of these 3 post. https://newhelptech.wordpress.com/2017/07/02/step-by-step-implementing-storage-spaces-in-windows-server-2016/

https://barreto.home.blog/2015/02/08/using-powershell-to-select-physical-disks-for-use-with-storage-spaces/

https://docs.microsoft.com/en-us/powershell/module/storage/?view=win10-ps

IMO Storage Spaces on a single server still has some growing up to hopefully do.

Hang in there

Edit to add this post

https://barreto.home.blog/2014/11/19/storage-spaces-survival-guide-links-to-presentations-articles-blogs-tools/

I have been running a setup with 2x SSD (mirror) and 4x HDD (parity) for many years first on Windows Server 2012 R2 later 2016 without any issues and great performance... especially combined with deduplication!

I can't find the script that I used to configure them as I haven't used them for... well, many years... So I used my Google-Fu and found this great write up that looks like the right stuff: https://www.starwindsoftware.com/blog/configure-a-resilient-volume-on-windows-server-2016-using-storage-spaces

Ps. I also remember having to fiddle with the sizes to get the command to complete as you can't just use the size directly from reported size... so try and start at the reported size and then go down mayb 5G at a time until it succeeds and then go up 1GB at a time until you nail the sweetspot if you want full utilization 😉

Hope this helps you get it up and running