Space Reclamation not working

[OmotayoZadok]

Hi,

I have a thinly provisioned LUN from my FAS2552 to a Windows Server 2019, with hyper-V role installed.

On the server, it shows that the free space is 246GB. However on the storage, we have about 178GB left.

I have run the commands on the Storage SSH to fix this. (I disabled and enabled the space-allocation feature)

ONTAP version is 9.5P17.

Please help me with suggestions to fix this anomaly.

[pedro_rocha]

Hi,

Did you check this KB? 

https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/ONTAP_and_Windows_SCSI_unmap_and_space_reclamation

It does not list 2019, but I guess is just out dated.

Also, when setting space-allocation, are you putting the LUN offline and re-discovering it?

[OmotayoZadok]

Yes. I set the LUN to be offline before running the command

[jaikumar]

To confirm if  after enabling space allocation  , you can check if the counters related to space reclamation operations at the hosts incremented in the target

• unmap_reqs 

These counters are in the lun object 

e.g statistics show -object lun -instance <lun path> -raw -counter *unmap*

(space reclamation sends scsi unmap commands to the target and scsi unmap requests is expected to increment the above counter)