== sanity test 101b: check stride-io mode read-ahead =========================================================================== 00:04:45 (1788667485)
striped dir -i1 -c2 -H crush  /mnt/lustre/d101b.sanity

1.926855s, 4.35352MB/s
Read-ahead success for size 8192

1.785199s, 4.69898MB/s
Read-ahead success for size 16384

2.268389s, 3.69805MB/s
Read-ahead success for size 32768

1.556636s, 5.38893MB/s
Read-ahead success for size 65536

1.769955s, 4.73945MB/s
Read-ahead success for size 131072

1.452974s, 5.77341MB/s
Read-ahead success for size 262144

1.470742s, 5.70366MB/s
Read-ahead success for size 524288

1.455376s, 5.76388MB/s
Read-ahead success for size 1048576