Hi Jens,

 I am seeing a strange problem. I have a 47KB Blkparsed binary file
and I tried replaying it with and without the "replay_no_stall"
option.

With the "replay_no_stall" option, I am seeing some IOPS
happening.Please see below.
WITH "REPLAY_NO_STALL=1"
============================================================
job9: (g=0): rw=read, bs=4K-4K/4K-4K/4K-4K, ioengine=sync, iodepth=1
fio-2.1.7
Starting 1 process
Jobs: 1 (f=2): [M] [-.-% done] [1064KB/72KB/0KB /s] [266/18/0 iops]
[eta 00m:00s]
job9: (groupid=0, jobs=1): err= 0: pid=34226: Thu Apr 10 12:00:54 2014
  read : io=3792.0KB, bw=1126.3KB/s, iops=281, runt=  3367msec
    clat (usec): min=88, max=8536, avg=3546.19, stdev=1469.46
     lat (usec): min=88, max=8536, avg=3546.35, stdev=1469.47
    clat percentiles (usec):
     |  1.00th=[  141],  5.00th=[  270], 10.00th=[ 1800], 20.00th=[ 2320],
     | 30.00th=[ 2800], 40.00th=[ 3216], 50.00th=[ 3664], 60.00th=[ 4048],
     | 70.00th=[ 4512], 80.00th=[ 4896], 90.00th=[ 5344], 95.00th=[ 5600],
     | 99.00th=[ 6176], 99.50th=[ 6560], 99.90th=[ 8512], 99.95th=[ 8512],
     | 99.99th=[ 8512]
    bw (KB  /s): min= 1027, max= 1280, per=100.00%, avg=1129.00, stdev=99.47
  write: io=212992B, bw=63258B/s, iops=15, runt=  3367msec
    clat (usec): min=39, max=65, avg=44.27, stdev= 4.10
     lat (usec): min=40, max=66, avg=44.92, stdev= 4.16
    clat percentiles (usec):
     |  1.00th=[   39],  5.00th=[   39], 10.00th=[   40], 20.00th=[   41],
     | 30.00th=[   42], 40.00th=[   43], 50.00th=[   43], 60.00th=[   45],
     | 70.00th=[   46], 80.00th=[   47], 90.00th=[   48], 95.00th=[   50],
     | 99.00th=[   65], 99.50th=[   65], 99.90th=[   65], 99.95th=[   65],
     | 99.99th=[   65]
    bw (KB  /s): min=   48, max=   79, per=100.00%, avg=63.17, stdev=11.03
    lat (usec) : 50=4.90%, 100=0.40%, 250=4.30%, 500=1.40%, 750=0.10%
    lat (msec) : 2=6.90%, 4=42.70%, 10=39.30%
  cpu          : usr=0.00%, sys=0.45%, ctx=1002, majf=0, minf=2
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued    : total=r=948/w=52/d=0, short=r=0/w=0/d=0
     latency   : target=0, window=0, percentile=100.00%, depth=1
=========================================================
However, when I don't set the "REPLAY_NO_STALL" option, I see 0
IOPS.Please see below
job9: (g=0): rw=read, bs=4K-4K/4K-4K/4K-4K, ioengine=sync, iodepth=1
fio-2.1.7
Starting 1 process

job9: (groupid=0, jobs=1): err= 0: pid=33979: Thu Apr 10 10:39:42 2014
  read : io=3792.0KB, bw=2004B/s, iops=0, runt=1937594msec
    clat (usec): min=87, max=14320, avg=4763.37, stdev=2001.45
     lat (usec): min=87, max=14320, avg=4763.52, stdev=2001.50
    clat percentiles (usec):
     |  1.00th=[  199],  5.00th=[ 1624], 10.00th=[ 2256], 20.00th=[ 3088],
     | 30.00th=[ 3760], 40.00th=[ 4320], 50.00th=[ 4832], 60.00th=[ 5280],
     | 70.00th=[ 5728], 80.00th=[ 6496], 90.00th=[ 7264], 95.00th=[ 7840],
     | 99.00th=[ 8896], 99.50th=[10304], 99.90th=[14272], 99.95th=[14272],
     | 99.99th=[14272]
    bw (KB  /s): min=    0, max=   23, per=100.00%, avg= 3.24, stdev= 4.87
  write: io=212992B, bw=109B/s, iops=0, runt=1937594msec
    clat (usec): min=39, max=62, avg=48.46, stdev= 6.93
     lat (usec): min=39, max=64, avg=49.19, stdev= 7.36
    clat percentiles (usec):
     |  1.00th=[   39],  5.00th=[   39], 10.00th=[   40], 20.00th=[   42],
     | 30.00th=[   44], 40.00th=[   45], 50.00th=[   46], 60.00th=[   50],
     | 70.00th=[   54], 80.00th=[   57], 90.00th=[   58], 95.00th=[   59],
     | 99.00th=[   62], 99.50th=[   62], 99.90th=[   62], 99.95th=[   62],
     | 99.99th=[   62]
    bw (KB  /s): min=    0, max=    1, per=100.00%, avg= 0.09, stdev= 0.30
    lat (usec) : 50=3.10%, 100=2.20%, 250=3.40%, 500=0.40%, 750=0.10%
    lat (msec) : 2=3.10%, 4=25.20%, 10=62.00%, 20=0.50%
  cpu          : usr=0.00%, sys=0.00%, ctx=1066, majf=0, minf=2
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued    : total=r=948/w=52/d=0, short=r=0/w=0/d=0
     latency   : target=0, window=0, percentile=100.00%, depth=1
=============================================================

My starting time in the blkparsed binary file is 26.040173218 seconds
and last time is 26.150699031.

Attached is the binary file I am using to replay.

I understand replay_no_stall option doesnt respect the timestamps, but
without this option the job should be executing with the delays, and
not sure why no OPS are reported.

Any idea what is causing this strange behavior?Please help.

Thanks,
Lakshmi