I don't understand what is going on here, but I found this which seems relevant, tho from 2015.
Sorry if it's not helpful. I agree w Overmind-it would be nice if MS gave us some idea what's going on.
https://social.technet.microsoft.com/Forums/windows/en-US/acfb74a7-1f01-4705-8146-0f2589b54ef6/question-about-amount-of-parity-in-storage-pool?forum=w8itprogeneral
I raised this nearly a week ago with MS Support and they yesterday they confirmed it as a bug.
Well as I needed to progress this issue I had to devote some more of my own time to it. I created a new build in my lab with 8 physical disks available to pool and spent some time testing various configurations and commands. What I have found is that it is isolated to a bug in the Storage Spaces GUI; i.e. the underlying PowerShell Storage cmdlets are working as expected.
Here are the steps I took to achieve my desired result:
- Create a Storage Pool of all required disks (in this case 8x68GB, named "JStore") - this can be done via GUI or Shell
- From an administrative PowerShell session run this command:
New-VirtualDisk -FriendlyName "Parity_Max_Auto" -StoragePoolFriendlyName JStore -UseMaximumSize -ResiliencySettingName Parity -AutoNumberOfColumns
- Run Get-VirtualDisk to confirm success:
FriendlyName ResiliencySettingNa OperationalStatus HealthStatus IsManualAttach Size
me
Parity_Max_Auto Parity OK Healthy False 469 GB
- Run Get-VirtualDisk | Get-Disk | Initialize-Disk
- Run Get-VirtualDisk | Get-Disk to get the disk number (in this case 10)
- Run New-Partition -DiskNumber 10 -UseMaximumSize -AssignDriveLetter to create a new partition
- Run Format-Volume -DriveLetter F -FileSystem NTFS to format the volume
This series of commands creates a parity space with a 1/n parity allocation as expected giving 469GB usable in this instance, which equates to 1/8. I'm going to try and apply it to my 9TB build tonight and see what happens there. It worries me that Win8 can get to RTM with this bug still apparent, but I hope this at least helps someone else to utilise Storage Spaces properly.
Cheers
Proposed as answer by stlc8tr Thursday, October 22, 2015 9:17 PM
Tuesday, October 2, 2012 4:13 PM
jazzrobot
next post--
I've had confirmation from MS that this is a bug in the GUI element of Storage Spaces on Win8. The underlying PowerShell Storage cmdlets function as expected, and you should be able to create your Storage Space using PowerShell. Once created, management can be done via the shell or the GUI, as it seems to be only the creation wizard that is affected by the bug.