Windows 10 Pro 2004 - Removing a disk from fully mirrored Storage Pool is not possible - low space
Scenario: Windows 10 2004 1 Storage Pool Storage Pool functional level: vServerNext Pool consists of 2 x 6TB same Harddisk 2 virtual Disks (DATA, BACKUPS) Thin provisioned, NTFS, Default Cluster size The pool usage was 4,81 TB out of 10,9 TB (before adding a 3rd disk) Disk usage was balanced 43-44,1% Defrag Storage Space efficiency (slab consolidation) is 98%-99% What I am trying to do: I need to remove one disk for maintenance As the virtual disks are both mirrored I suspect this would be possible, but it is not. What I did so far: #save object of disk $PDtoRemove = Get-PhysicalDisk -serialnumber SerialNr #set disk as retired for removal Set-PhysicalDisk $PDtoRemove -Usage Retired #idenfity the used virtual disks for this physical disk Get-PhysicalDisk $PDtoRemove | Get-VirtualDisk #prepare for drive removal Repair-VirtualDisk -FriendlyName 'Data' Repair-VirtualDisk -FriendlyName 'Backups' What troubles me: #check jobs Get-StorageJob Shows both repair jobs as suspended. GUI shows - needs more disk space. Removing the disk with Remove-PhysicalDisk $PDtoRemove Output: - Not enough available capacity Storage pool dos not have sufficient capacity to relocate data from the specified disk (remark: see Job suspended) recommended actions: - add more physical disks to the storage pool, S - free capacity by deleting unneeded virtual disk This leaves me alone if I understood the concept of Storage Spaces Mirror, is equivalent of RAID 1, where I could remove / fail one drive anytime. Even more here the capacity has not even reached 50% What I expect to happen For a mirror, expect some metadata overhead for the pool and virtual volume this should not make a different, imho. It should tolerate this operation or a fail. I don't want to imagine what happened if a drive really failed out of the blue.
How does Windows Storage Spaces Columns work?
I can't find explanation on how Windows uses columns in Storage Spaces. I have originally thought it works like this: I create pool with parity virtual-disk with 3 columns, 3 drives, giving it capacity of 2 drives or 66 percent efficiency. I add 3 more drives of the same capacity into the pool and extend the virtual-disk, which will again allow me to use additional capacity of the 2 drives I added. Now I'm getting lost. When I start writing data to this expanded virtual-disk, does it split every write into 2 rows, and every row into 2 columns and then calculates parity for each row? That's what I originally thought, but then Windows asked me to add 2 drives into 3-column parity Storage Space, for a total of 7 drives, which makes no sense to me. What am I missing? How does Storage Spaces write data?
