When using create_thin with dmsetup command, receiving error that file exists

Issue

• When using create_thin with dmsetup command, receiving error that file exists

  # dmsetup create mdata --table '0 2097152 linear /dev/sda 0'
  # dmsetup create data --table '0 2097152 linear /dev/sdb 0'
  # dmsetup create pool --table '0 2097152 thin-pool /dev/mapper/mdata /dev/mapper/data 128 0'
  # dmsetup message /dev/mapper/pool 0 "create_thin 20"
  # dmsetup create thinvol --table "0 200000 thin /dev/mapper/pool 20"
  
  # dmsetup remove thinvol
  # dmsetup remove pool
  # dmsetup remove data
  # dmsetup remove mdata
  
  # dmsetup create mdata --table '0 2097152 linear /dev/sda 0'
  # dmsetup create data --table '0 2097152 linear /dev/sdb 0'
  # dmsetup create pool --table '0 2097152 thin-pool /dev/mapper/mdata /dev/mapper/data 128 0'
  # dmsetup message /dev/mapper/pool 0 "create_thin 20"
  device-mapper: message ioctl on pool  failed: File exists
  Command failed.