== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 02:39:47 (1781246387)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17740     1253564   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10452     1260852   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       20700     3586320   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       22900     3584120   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170440   1%  /mnt/lustre