Yes, after setting factional reserve to 0 the space was immediately freed up. I guess after working with netapps for 20+ years I still don't understand factional reserve. Perhaps no one does 🙂
The unanswered question is why the factional reserve claimed 23+ TB for the volume when it only has one LUN on it, reservation is *on* for the LUN, so the vol should only need 16TB for the LUN plus some space (6+ TB?!?) for metadata and deduplication. (The LUN is 99% full but reservation should make that irrelevant.) "vol show-footprint" and "vol show-space" didn't hint at that.
I am still mystified why "show footprint" showed this
netapp-clr301::> vol show-footprint -volume VMDK_01
Vserver : netapp-iscsi301
Volume : VMDK_01
Feature Used Used%
-------------------------------- ---------- -----
Volume Data Footprint 5.88TB 10%
Volume Guarantee 16.93TB 30%
Flexible Volume Metadata 131.1GB 0%
Deduplication 8KB 0%
Delayed Frees 235.9GB 0%
Total Footprint 23.17TB 41%
when the 99% full 16TB LUN on the volume, with reservation on, is the only thing on the volume.