lvdisplay

  --- Logical volume ---
  LV Path                /dev/lvm/sage-fs
  LV Name                sage-fs
  VG Name                lvm
  LV UUID                O85w4p-qLmj-COwx-cL2c-2F33-vknW-Ijo3Ru
  LV Write Access        read/write
  LV Creation host, time gauss, 2012-09-24 11:48:36 +0200
  LV snapshot status     active destination for sage-fs_vorigin
  LV Status              available
  # open                 0
  LV Size                100,00 GiB
  Current LE             25600
  COW-table size         20,00 GiB
  COW-table LE           5120
  Allocated to snapshot  16,87%
  Snapshot chunk size    4,00 KiB
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:7