Yes, I wasn't clear enough on that. You can build truly large clusters or even single server system with Storage Spaces. I gave the impression is was limited to 8 drives but that's not what I meant.
http://social.technet.microsoft.com/wiki/contents/articles/11382.storage-spaces-frequently-asked-questions-faq.aspx
Scroll down a bit more than half way to the chart. In the Resiliency type column go down to Single Parity and then look at the far right column "Maximum Column Count".
You'll see for single parity the maximum column count is 8. <-- That is what I was getting at. For dual parity you can go up to 17 columns.
So even with single parity I could have 9, 10, 11 or 12 drives. In case it's not clear here's an example with 12 drives using 8 columns for a series of writes. The number below would show how each drive is used.
1,2,3,4,5,6,7,8 (first write to disk)
2,3,4,5,6,7,8,9 (second write to disk)
3,4,5,6,7,8,9,10 (third write to disk)
4,5,6,7,8,9,10,11 (forth write to disk)
5,6,7,8,9,10,11,12 (fifth write to disk)
1,2,3,4,5,6,7,8 (sixth write to disk)
2,3,4,5,6,7,8,9
3,4,5,6,7,8,9,10
4,5,6,7,8,9,10,11
5,6,7,8,9,10,11,12
So it alternates the uses of the disks but in the case of single parity will only use 8 at any one time. All drives will get equally used. So as you can see, storage spaces can and will use all 12 drives but each read or write will only use 8 drives at a time since I'm using single parity which supports a maximum of 8 columns. This could have been 20 or 30 disks. It would just follow the same type of pattern only using any 8 at one time.
You could do the same exercise as above with 17 drives using dual parity.
You can do things like setup 16 disks in dual parity mode then mirror this for a total of 32 drives in use. It's really flexible. In configurations like this one even with NTFS you can get almost all the features of ZFS because storage spaces can use the parity information along with the 2nd set of data to autofix almost anything wrong with the data including true bitrot in real-time without the typical overhead of ZFS or even ReFS.
So Storage Spaces is almost endlessly scale-able for our use and why I use it. I hope that explained a bit better what I was getting at without confusing things further concerning 8 columns. :)
It really is very flexible in setup and use of hardware. You can mix and match SAS, SATA and USB (USB3 for performance). You can mix and match different sizes of discs also.
Carlo