text: The only parameter except virtual capacity that is available on a volume level to monitor thin, 
  compressed, or deduplicated volume, is used_capacity_before_reduction. It indicates the 
  total amount of data written to a thin-provisioned or compressed volume copy in a data 
  reduction storage pool before data reduction occurs. This field is empty for fully allocated 
  volume copies and volume copies not in a data reduction pool. Capacity that is assigned to 
  the volume in the tier is also not reported. 
  
  To find this value, use the**lsvdisk**command with volume name or ID as a parameter, as 
  shown in Example 10-9. It shows a non-compressed thin-provisioned volume with virtual size 
  100 GiB on a DRP pool, which was mounted to a host, and had a 72 GiB file created on it. 