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<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">Hi Kent,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">I have tested bcache on my platform, but the result is not good. I think maybe the wrong config caused it. Would you pls help me to check the config, or give me some advice for bcache
performance testing?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">My SSD card is a PCIe SSD card (about 120,000 IOPS), and I used 10GB.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">I have download the code from git://evilpiepirate.org/~kent/linux-bcache.git.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">The commands creating bcache is below:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">make-bcache –B /dev/sdb8<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">make-bcache –C –w4k –b1M –writeback /dev/hioa5
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">I use FIO to test the seq./random IO performance, and the result is below:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:84.0pt"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">write read randwrite randread<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">bcache 10809 KB/s 164502.5 KB/s 2713 KB/s 29640 KB/s<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">cache_hit_rate 80 79 94 92<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">And the basic test result is:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:42.0pt"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">Write read randwrite randread<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">HDD 81211.6 KB/s 172242 KB/s 2606 KB/s 1855 KB/s<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;color:#1F497D">SSD 250948.2 KB/s 813855 KB/s 238892.7 KB/s 657319.5 KB/s<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt"><o:p> </o:p></span></p>
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