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