== sanity test 56Dc: test 'lfs df -o' only shows OST devices ========================================================== 00:31:59 (1786681919)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11356     1259948   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16232     1255072   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26832     3580104   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16772     3590108   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170212   1%  /mnt/lustre