Server 2012 Storage Spaces - Displaying Incorrect Pool Capacity

Question

I have a physical 2012 R2 server with 98.2 TB internal storage. Specifically, it's running Veritas Backup Exec 20.5 1188.

The storage area has been defined with Storage Spaces and this consists of a single Pool with x3 24 TB virtual disks to store the backup data. Backups started failing because a couple of drives were disconnecting, so I reconnected them and deleted a load of old data to free up space. I'd hoped that by freeing up space this would resolve the issue, however the disks still dropped off when the backups run.

When I look at the Storage Pool it says 92.4 % used, despite clearing several terabytes of data from all three disks. My suspicions point to 'Pool Capacity Used', and this might be causing the drives to disconnect when the backups start, maybe because it thinks the Storage Pool is nearly full, even though it isn't?

The disks use Fixed Provisioning, so I wouldn't expect this kind of issue unless I was using Thin Provisioning, where this is a known problem.

Answer 1

Hi,
Please run the following commands and attach your screenshots:
Get-StoragePool -IsPrimordial $False | Select-Object HealthStatus, OperationalStatus, ReadOnlyReason
Get-VirtualDisk | Select-Object FriendlyName,HealthStatus, OperationalStatus, DetachedReason
Get-PhysicalDisk
What is the resiliency type of your storage space, simple, mirror or parity?
Sometimes the Storage space's Shadow copies may cause such issue, you can try to open the Dashboard, right click on the drive, click "View the hard drive properties"-"Shadow Copies" tab, and unchecked the box, which may free the space.

Thanks for your time!
Best Regards,
Mico Mi

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Answer 2

Hi,
The capacity of storage pool shows the total physical space used on the underlying hardware and you can see your physical space is nearl full.
Since you are using Fixed Provisioning disks, the space of virtual disks is carved out of the available physical storage pool.
To check if the issue is related to the space of disks, you can try to configure shadow copy jobs using those disks and see if it works.

Also I found some information about freeing the physical space:
To free the physical storage space it is necessary for the virtual disk to both release the unused sectors (thru TRIM and UNMAP commands) to the underlying storage and for the physical storage to be released and possibly defragmented to consolidate the still used storage to a single contiguous block. This is called dead space reclamation.
This command will release the unused sectors on the virtual disk and release the “unused” slabs back to the storage space pool.
Optimize-Volume -DriveLetter D: -ReTrim -SlabConsolidate -Verbose
(https://learn.microsoft.com/en-us/powershell/module/storage/optimize-volume?view=win10-ps)

Best regards,
Mico Mi