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5.4.16.4. Converting a Mirrored LVM Device to a RAID1 Device

You can convert an existing mirrored LVM device to a RAID1 LVM device with the lvconvert command by specifying the --type raid1 argument. This renames the mirror subvolumes (*_mimage_*) to RAID subvolumes (*_rimage_*). In addition, the mirror log is removed and metadata subvolumes (*_rmeta_*) are created for the data subvolumes on the same physical volumes as the corresponding data subvolumes.
The following example shows the layout of a mirrored logical volume my_vg/my_lv. 
# lvs -a -o name,copy_percent,devices my_vg
  LV               Copy%  Devices                      
  my_lv             15.20 my_lv_mimage_0(0),my_lv_mimage_1(0)
  [my_lv_mimage_0]        /dev/sde1(0)                 
  [my_lv_mimage_1]        /dev/sdf1(0)                 
  [my_lv_mlog]            /dev/sdd1(0)
The following command converts the mirrored logical volume my_vg/my_lv to a RAID1 logical volume. 
# lvconvert --type raid1 my_vg/my_lv
# lvs -a -o name,copy_percent,devices my_vg
  LV               Copy%  Devices                      
  my_lv            100.00 my_lv_rimage_0(0),my_lv_rimage_1(0)
  [my_lv_rimage_0]        /dev/sde1(0)                 
  [my_lv_rimage_1]        /dev/sdf1(0)                 
  [my_lv_rmeta_0]         /dev/sde1(125)               
  [my_lv_rmeta_1]         /dev/sdf1(125)