I built myself a NAS\SAN in my test lab using Windows Server 2012 Storage Spaces, a WD Black 1.5TB disk and a WD Green 2TB disk, Initially this worked well. With the success I decided to upgraded the physical disks to WD Red 3TB disks the process of adding the WD Red disks appeared to go smoothly and I was able to see the new storage from my virtual hosts.
A couple of days later I was preping to migrate the data from my WD Black to the new WD Reds before doing so I rebooted the server. Upon reboot within Server Manger – File and Storage Services – Storage Pools I noticed a yellow warning triangle next to my virtual disks.
My virtual disks had become detached and would not reattach as I was told the disk and name were already in use in the system.
After spending some time attempting to re-add the disks I tried some of the Powershell commands to diagnose the problem.
Upon running the Get-VirtualDisk command I noticed that the ISManualAttach values were set to TRUE which did not sound right.
Upon searching for the Set-VirtualDisk parameters (http://technet.microsoft.com/en-us/library/hh848712.aspx) I was able to change this setting by using the following command in PowerShell.
Set-VirtualDisk -FriendlyName yourdiskname -IsManualAttach $False
I checked the settings had changed by running another Get-VirtualDisk and they had.
Upon rebooting and checking in Storage Pools my disks were attached and all my volumes and iSCSI disks were restored.