From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:48192 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751562AbdBNEQn (ORCPT ); Mon, 13 Feb 2017 23:16:43 -0500 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1cdUXZ-0004Vl-1J for fio@vger.kernel.org; Tue, 14 Feb 2017 05:16:33 +0100 From: Slow bucks Subject: basic verify - output shows start with read then write? Date: Mon, 13 Feb 2017 22:16:29 -0600 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: fio@vger.kernel.org Strange but during a verify job the output shows that it executed the verify/read operation first then write: randw/verify: (groupid=0, jobs=1): err= 0: pid=1647: Tue Feb 14 04:08:08 2017 read : io=10240MB, bw=64801KB/s, iops=63, runt=161816msec slat (usec): min=48, max=16277, avg=423.53, stdev=2263.87 clat (msec): min=18, max=860, avg=488.46, stdev=34.60 lat (msec): min=18, max=860, avg=488.88, stdev=34.65 clat percentiles (msec): | 1.00th=[ 461], 5.00th=[ 461], 10.00th=[ 465], 20.00th=[ 478], | 30.00th=[ 482], 40.00th=[ 482], 50.00th=[ 482], 60.00th=[ 482], | 70.00th=[ 498], 80.00th=[ 498], 90.00th=[ 498], 95.00th=[ 519], | 99.00th=[ 619], 99.50th=[ 701], 99.90th=[ 783], 99.95th=[ 824], | 99.99th=[ 840] write: io=10240MB, bw=54791KB/s, iops=53, runt=191378msec slat (usec): min=29, max=16341, avg=548.59, stdev=2596.46 clat (msec): min=17, max=1238, avg=578.37, stdev=61.50 lat (msec): min=17, max=1239, avg=578.92, stdev=61.52 clat percentiles (msec): | 1.00th=[ 478], 5.00th=[ 502], 10.00th=[ 519], 20.00th=[ 523], | 30.00th=[ 537], 40.00th=[ 603], 50.00th=[ 603], 60.00th=[ 603], | 70.00th=[ 603], 80.00th=[ 619], 90.00th=[ 619], 95.00th=[ 627], | 99.00th=[ 742], 99.50th=[ 873], 99.90th=[ 1057], 99.95th=[ 1106], | 99.99th=[ 1237] bw (KB /s): min= 1549, max=69493, per=99.92%, avg=54747.92, stdev=5798.57 lat (msec) : 20=0.01%, 50=0.01%, 100=0.05%, 250=0.12%, 500=48.41% lat (msec) : 750=50.80%, 1000=0.48%, 2000=0.11% I used the example from here: https://github.com/axboe/fio/blob/master/examples/basic-verify.fio Isn't the results suppose to show the write activity first then the verify/read?