DataCore thin provisioning and vSphere Thin provisioning, is there an issue

[juchestyle]

Hey Everyone,

Question:  If Datacore is thin provisioned (storage layer), and VM's are thin provisioned (VMWare layer); is there an issue if:

•     A VM is thick provisioned and then thin provisioned back?

I have heard there is a concern that if this is done, there is lost storage at the storage layer?

Has anyone run across this or heard of it before?  I was told under these circumstances a process needs to be run at the storage layer to "RECLAIM," the storage after a process like this.

Any insight you may have on this is greatly appreciated.

Thank you,
Matthew

[Maximilian Brendler]

Hey juchestyle,

we have an issue with thin on thin provisioning.

In our environment we use a HP 3PAR 7400 and VMware vSphere ESXi 5.5.

Let me describe the issue in 4 simple steps:

1. Take a vm (thin provisioned vmdk) with an attached vmware-snapshot

2. Clone it with vmware-means to a newly thin provisioned volume

3. Delete the clone

4. Clone again to the same target-volume

Result: The second cloning takes way longer than the first. Doing an UNMAP (that´s the spacereclaimation "esxcli storage vmfs unmap -l DATASTORELABLE") between 3 and 4 makes the second cloning as fast as the first one.

I just posted our issue today (poor cloning performance at thin provisioning - takes forever!) and hope anybody got an idea to resolve it.

If you have similiar experience I would be glad to have an exchange with you...

Thanks,

Max