very cool, so if I add the changes to init.c and run fio --latency-log --output test.job I get extra four files -rw-r--r-- 1 me staff 14937 Aug 8 2012 fiotest_lat.log -rw-r--r-- 1 me staff 0 Aug 8 2012 fiotest_slat.log -rw-r--r-- 1 me staff 14932 Aug 8 2012 fiotest_clat.log -rw-r--r-- 1 me staff 4194304 Aug 8 2012 fiotest.1.0 What's the format? $ more fiotest_lat* 1, 19, 1, 4096 1, 18, 1, 4096 1, 8, 1, 4096 1, 7, 1, 4096 1, 7, 1, 4096 What's the format? OK, found http://www.spinics.net/lists/fio/msg01064.html Format of entries is: time, rate/latency, data direction, block size Time: in milliseconds. Bandwidth logs are usually 500 or 1000ms apart; that can be controlled by the config file with "bwavgtime=[x ms]". Rate/latency: for bandwidth, this is in KB/sec. For latency, it's microseconds. Data direction: 0 is read, 1 is write. Block size: block size of IOs in bytes. the clat and lat look pretty much the same except clat is faster than lat (clat is completion time ie submission time plus I/O completion time - was never that clear on this) $ paste fiotest_lat* fiotest_c* | more 1, 19, 1, 4096 1, 17, 1, 4096 1, 18, 1, 4096 1, 17, 1, 4096 1, 8, 1, 4096 1, 7, 1, 4096 1, 7, 1, 4096 1, 6, 1, 4096 1, 7, 1, 4096 1, 6, 1, 4096 what is the format of the file fiotest.1.0 ? Is there a way to get the latency files without this file to avoid too much output. Thanks - Kyle On Tue, Aug 7, 2012 at 7:47 AM, Mike Ryan wrote: > On Tue, Aug 07, 2012 at 03:43:06PM +0200, Jens Axboe wrote: > > > fio --latency-log=/tmp/log --output=/tmp/log random_write.fio > > > > The latency/bw logs are named from the job name, so you can't actually > > give it a specific name with the (global) command line option. You'd > > need to use the job option to do that. > > The argument requires an option. It appears that option is discarded. > > > That said, it does look broken in that we don't inherit the global > > setting. Does the below make it work? > > Yes! The files are named log_lat.log, log_slat.log, and log_clat.log. > They are not named after the job. > -- > To unsubscribe from this list: send the line "unsubscribe fio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- - Kyle O: +1.415.341.3430 F: +1.650.494.1676 275 Middlefield Road, Suite 50 Menlo Park, CA 94025 http://www.delphix.com