== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 17:06:43 (1782767203)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       18172     1253132   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11016     1260288   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       22844     3584092   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       20756     3586068   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170160   1%  /mnt/lustre