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<p class="MsoNormal"><span style="color:#1F497D">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Digging some more, dropping Linux cache after every write and then doing read, makes my iostat show values signifying that reads are happening from disk.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">This is quite strange as I have used direct=1 and also performance.strict-o-direct is ON. Doesn’t this both option disable Linux page cache?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Any inputs on this would be useful.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">-Prashanth<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="mso-fareast-language:EN-IN">From:</span></b><span lang="EN-US" style="mso-fareast-language:EN-IN"> Prashanth Kumar N
<br>
<b>Sent:</b> 21 January 2016 14:36<br>
<b>To:</b> 'gluster-users@gluster.org'<br>
<b>Subject:</b> Issue in reading data using fio + gfapi<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have been trying to use gfapi to read files written using fio gfapi engine, but don’t see anything getting read. When I check disk activity using iostat or low level tools for my PCIe SSD, there is no activity.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is the below sequence of fio correct way of using it? Am I missing something?
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[root@vsan-blr4 prashanth]# fio --name=seq_write.1.0 --filename=seq_write.1.0 --rw=read --ioengine=gfapi --direct=1 --bs=4K --iodepth=1 --numjobs=8 --group_reporting --volume=pvol --brick=192.168.1.3 --time_based=40 --size=1G<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">fio: time_based requires a runtime/timeout setting<o:p></o:p></p>
<p class="MsoNormal">seq_write.1.0: (g=0): rw=read, bs=4K-4K/4K-4K/4K-4K, ioengine=gfapi, iodepth=1<o:p></o:p></p>
<p class="MsoNormal">...<o:p></o:p></p>
<p class="MsoNormal">fio-2.2.10<o:p></o:p></p>
<p class="MsoNormal">Starting 8 processes<o:p></o:p></p>
<p class="MsoNormal">Jobs: 8 (f=0): [R(8)] [inf% done] [0KB/0KB/0KB /s] [0/0/0 iops] [eta 1158050441d:07h:00m:13s]<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[ Note: As soon as I start the fio job, I see a huge ETA number which seems fishy and fio exits in less than 5 seconds. ]<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal">Prashanth<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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