== sanity test 56Dc: test 'lfs df -o' only shows OST devices ========================================================== 00:32:21 (1788841941)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11164     1260140   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16024     1255280   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       31024     3575996   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12580     3594412   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170408   1% /mnt/lustre