== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 01:28:33 (1782365313)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17116     1254188   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       20988     1250316   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       23452     3583568   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       21116     3585904   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44568     7169472   1%  /mnt/lustre