We recently realized the free space value on a single datastore in our VMware datastore cluster wasn’t matching the value of free space we were seeing on the backing device sitting on your VPLEX arrays. Not even close, as a matter of fact the underlying VLPEX distributed volume was fully utilized.

This clearly suggested something was going wrong with the deleted block unmap process.

To troubleshoot I jumped on a ESX host which has access to the particular datastore and run some esxcli cmds.

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