Run the following command to confirm that zeroing is enabled precisely.
Zero status should be supported.
~ # esxcli storage core device vaai status get
naa.600601601a902c0012a4a38b1b07e211
VAAI Plugin Name: VMW_VAAIP_CX
ATS Status: supported
Clone Status: supported
Zero Status: supported
Delete Status: unsupported
yes, you dont need to use vmkfstool. Just create a VM with eagerzoroeddisk or add a eagerzoroeddisk harddisk to the existing VM. you can fee the difference in performance with VAAI and without VAAI by seeing the time taken to create the VMDK.
Read out the following DOC from EMC for clear understanding about VAAI. the principle is same for all storages though its written from EMC VMAX.
http://uk.emc.com/collateral/hardware/white-papers/h8115-vmware-vstorage-vmax-wp.pdf
>>> but why datacore and esx see different space?
I am not sure why this difference. Its unusual.
Can you run the following command and compare the Size in the output?
esxcfg-scsidevs -c
