== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 15:20:03 (1780860003)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       15528     1255776   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       18984     1252320   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       32620     3574400   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       11956     3595064   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44576     7169464   1%  /mnt/lustre