# zfs get all volume03 | grep used
volume03  used                  9.97T                  -
volume03  usedbysnapshots       0                      -
volume03  usedbydataset         12.9M                  -
volume03  usedbychildren        9.97T                  -
volume03  usedbyrefreservation  0                      -
volume03  logicalused           6.95T