On 04/02/2014 11:53 AM, Mark Nelson wrote:
On 04/02/2014 12:38 PM, Jens Axboe wrote:
On 04/02/2014 09:23 AM, Mark Nelson wrote:
I've been playing around with usng the various write_*_log options in
fio to record run statistics. What I'm finding is that some of the logs
have malformed lines in them. The following snippet is from the bw log:
811820, 12263, 0, 4194304
812619, 35929, 0, 4194304
818437, 8448, 0, 419430, 4194304
1256299, 160627, 0, 4194304
1256831, 154274, 0, 4194304
Notice that the malformed line appears to be a partial write that gets
truncated. The fio command being used to run the tests is
autogenerated, so job files aren't used. here's the one that created
the above log snippet:
/home/nhm/bin/fio
--rw=read
--ioengine=libaio
--runtime=7200
--ramp_time=0
--numjobs=1
--direct=1
--bs=4194304B
--iodepth=16
--size=9216M
--write_iops_log=/tmp/cbt/ceph/kvmrbdfio/osd_ra-00004096/client_ra-00000128/op_size-04194304/concurrent_procs-008/iodepth-016/read/output
--write_bw_log=/tmp/cbt/ceph/kvmrbdfio/osd_ra-00004096/client_ra-00000128/op_size-04194304/concurrent_procs-008/iodepth-016/read/output
--write_lat_log=/tmp/cbt/ceph/kvmrbdfio/osd_ra-00004096/client_ra-00000128/op_size-04194304/concurrent_procs-008/iodepth-016/read/output
--time_based
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-0
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-1
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-2
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-3
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-4
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-5
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-6
--name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-7
The --numjobs=1 line should be removed, but I believe it gets overridden
anyway with multiple name parameters. I wonder if having multiple name
parameters (ie multiple fio processes) is causing those processes to all
try to write to the same log files, potentially at the same time? Any
thoughts would be much appreicated!
What version of fio are you running?
f42557f (ie master from yesterday) with a slightly different fix for the
basename issues that just got resolved.
I can verify now that running fio with a single --name flag appears to
generate logs without malformated lines.
OK, I'll take a look, We should already be serializing the writing to
the same log files, but your example definitely looks like we are not.
BTW, the numjobs option applies to each --name section. Just to clear
that up from your original email. So you really get numjobs *
name_sections running.
--
Jens Axboe
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