<br>As I said in my first email. dd test on raw SSD device reaches almost 100MB/s with 4k block size(which is almost 26,000 IOPS). I apologize that I haven`t mentioned the CPU utilization which is surprisingly low, all worker threads and receive threads consume less than 1% CPU individually. That why how I come up with the conclusion either my configuration is wrong or DRBD replication too slow. <br>
<br><br>Any suggestion is appreciated.<br><br>Ben<br> <br clear="all">Commit yourself to constant self-improvement<br>
<br><br><div class="gmail_quote">On Fri, Oct 29, 2010 at 1:01 PM, J. Ryan Earl <span dir="ltr"><<a href="mailto:oss@jryanearl.us">oss@jryanearl.us</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div class="im">On Fri, Oct 29, 2010 at 11:13 AM, Julien Escario <span dir="ltr"><<a href="mailto:escario@azylog.net" target="_blank">escario@azylog.net</a>></span> wrote: </div><div class="gmail_quote"><div class="im">
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Someone answered me that these preformances are perfectly normal is dual master configuration.<br></blockquote><div><br></div></div><div>Someone told you wrong.</div><div class="im"><div> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Seems to be due to the network latency (first server I/O + network latency + second server I/O + network latency (ACK))<br></blockquote><div><br></div></div><div>You should still be able to get much better than 97MB/sec. I get over 800MB/sec with a dual-primary with a backing store capable of ~950 MB/sec.</div>
<div class="im">
<div> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<br>
I finally decided that DRBD is unusable in dual primary setup because the performance drop.<br></blockquote><div><br></div></div><div>You were using 8.0.16, you should have tried with 8.3.x, 8.3 seems to do dual-primary a lot better in general.</div>
<div><br></div><font color="#888888"><div>-JR</div></font></div>
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