We are using VMWARE ESXi with a NetApp Filer. We have created Thin Provisioned LUNs on the NetApp and presented to VMWARE. I Storage vMotioned 10 Thick Provisioned VMs on the NetApp Storage and enabled DeDup. We decided we did not need the 10 VMs anymore and deleted from VMWARE and the Disk. In the NetApp Virtual Storage Console the LUN Usage is at 70%, but the Datastore Usage is 0%. Is there a way to reclaim the LUN space?
Space reclamation may be particularly useful in any environment that shows a large variance in the amount of data used. Systems used for queuing print jobs, e–mail, or standard file sharing are excellent candidates for space reclamation on a periodic schedule. Any system that has gone through a major change is also a good candidate for space reclamation. If you've performed database reorganization or made significant changes to a database because of archiving, space reclamation will likely recover a significant amount of data.
Getting Started with Space Reclamation
NetApp space reclamation technology has been integrated into NetApp SnapDrive® for Windows 5.0 and comes at no additional cost. SnapDrive makes it easy for Windows server administrators to manage NetApp SAN storage using either a wizard–based approach or through a command–line interface (SDCLI) that can be used in conjunction with management scripts and scheduling programs.
Using the SnapDrive GUI or SDCLI, you can periodically initiate the space reclamation process on your LUNs. The GUI tool will first determine how much space can be reclaimed and ask if you wish to continue. You can limit the amount of time the process will use to ensure that it does not run during peak periods.
Here are a few things to keep in mind when you run space reclamation:
I forgot to mention that these are not NFS LUNs they are FC LUNs. I see in the article it mentions NTFS, but is there a command to run on the Filer to reclaim the space?
Which version of ESXi and Ontap are you running ?
VAAI APIs are the way to go for space reclamation at the datatore level.
To be more there was the support for UNMAP in ESXi 5.0 but it has been dropped due to performances issues. You also
It has been reintroduced in a patched version as a manuel process
Given that you're datastore is empty you could remove the datastore from VMware then the LUN following this procedure
Then you recreate a new LUN using the VSC
Of course everything is related to you having ESXi 5.0 with latest patchs and Ontap 8.0.1+
Or you could you NFS
Unfortunately no, not until the VAAI for Space Reclamation is used and you are up to the required vSphere and DOT versions. However, all is not lost. Although the LUN usage in NetApp shows high (as far as we know the VMs are still there!) you will see the free space in the Datastore so you can place more VMs in the datastore.
With Dedupe, reclaiming the space should be less critical since each VM may not free up that much unique space but it will be nice when the VAAI option is available.
VAAI option depends on SCSI UNMAP function - VMware disabled it by default in ESXi 5.0 Patch 2.
In ESXi 5.0 U1 VMware brings it back, but advises to run space reclamation as a manual process during maintenance window: