== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 18:18:13 (1787869093)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       13456     1257848   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       18376     1252928   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       27052     3579968   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16532     3590236   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43584     7170204   1%  /mnt/lustre