== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 07:20:04 (1773746404)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17956     1253348   2%  /mnt/lustre[MDT:0]
lustre-MDT0001_UUID      1414116       24364     1246940   2%  /mnt/lustre[MDT:1]
lustre-OST0000_UUID      3833116       24568     3582452   1%  /mnt/lustre[OST:0]
lustre-OST0001_UUID      3833116       20060     3586960   1%  /mnt/lustre[OST:1]

filesystem_summary:      7666232       44628     7169412   1%  /mnt/lustre