I've noticed in my usage of DRBD if the rate exceeds the performance of the network between the nodes the sync rate sucks. Since rate is in bytes per second instead of bits per second a rate of 500MB/s would need 10GB ethernet and even 100MB/s would exceed the performance of GB Ethernet cards plugged into a standard PCI bus.<br>
<br>You might want to run iperf with the -f M parameter to get the actual performance of the sync network and use it to tune the rate values.<br><br><div class="gmail_quote">On Tue, Jun 2, 2009 at 4:56 PM, Sylvain Niles <span dir="ltr"><<a href="mailto:sniles@slingmedia.com">sniles@slingmedia.com</a>></span> wrote:<br>
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<div link="blue" vlink="purple" lang="EN-US">
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<p>I have tried everything under the sun and I can’t get
syncer to go faster that about 15Mbit/sec. Any hints would be greatly
appreciated as these devices are greater than 300G and initial sync is taking
forever at ~10-15M/sec. </p>
<p> </p>
<p>I’m running drbd82 and kmod-drbd82 (v8.2.6) on CentOS
5. Here’s the cleansed version of my drbd.conf:</p>
<p> </p>
<p>global { </p>
<p> usage-count no; </p>
<p>}</p>
<p>common {</p>
<p> protocol C;</p>
<p>}</p>
<p>resource mysql-01 {</p>
<p> syncer {</p>
<p> al-extents 3833;</p>
<p> rate 500M;</p>
<p> }</p>
<p> net {</p>
<p> max-buffers
8192;</p>
<p> }</p>
<p> disk {</p>
<p> no-disk-flushes;</p>
<p> no-md-flushes;</p>
<p> }</p>
<p> on mysql1 {</p>
<p> device /dev/drbd1;</p>
<p> disk
/dev/data1/mysql-01;</p>
<p> address <IP>;</p>
<p> meta-disk internal;</p>
<p> }</p>
<p> on mysql2 {</p>
<p> device /dev/drbd1;</p>
<p> disk
/dev/data1/mysql-01;</p>
<p> address <IP>;</p>
<p> meta-disk internal;</p>
<p> }</p>
<p>}</p>
<p>resource mysql -02 {</p>
<p> syncer {</p>
<p> al-extents 3833;</p>
<p> rate 100M;</p>
<p> }</p>
<p> net {</p>
<p> max-buffers
8192;</p>
<p> }</p>
<p> disk {</p>
<p> no-disk-flushes;</p>
<p> no-md-flushes;</p>
<p> }</p>
<p> on mysql1 {</p>
<p> device /dev/drbd2;</p>
<p> disk
/dev/data1/mysql-02;</p>
<p> address <IP>;</p>
<p> meta-disk internal;</p>
<p> }</p>
<p> on mysql2 {</p>
<p> device /dev/drbd2;</p>
<p> disk
/dev/data1/mysql-02;</p>
<p> address <IP>;</p>
<p> meta-disk internal;</p>
<p> }</p>
<p>}</p>
<p>resource mysql3 {</p>
<p> syncer {</p>
<p> al-extents 3833;</p>
<p> rate 100M;</p>
<p> }</p>
<p> net {</p>
<p> max-buffers
8192;</p>
<p> }</p>
<p> disk {</p>
<p> no-disk-flushes;</p>
<p> no-md-flushes;</p>
<p> }</p>
<p> on mysql1 {</p>
<p> device /dev/drbd3;</p>
<p> disk /dev/data1/mysql-3;</p>
<p> address <IP>;</p>
<p> meta-disk internal;</p>
<p> }</p>
<p> on mysql2 {</p>
<p> device /dev/drbd3;</p>
<p> disk /dev/data1/mysql-3;</p>
<p> address <IP>;</p>
<p> meta-disk internal;</p>
<p> }</p>
<p>}</p>
<p> </p>
<p>Thanks,</p>
<p>Sylvain Niles</p>
<p> </p>
</div>
</div>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Dwight Hubbard<br>Owner Effective Automation Solutions<br>Website: <a href="http://effectiveautomationsolutions.com">http://effectiveautomationsolutions.com</a><br>Blog: <a href="http://computing.dwighthubbard.info">http://computing.dwighthubbard.info</a><br>
Email: <a href="mailto:dwight@dwighthubbard.com">dwight@dwighthubbard.com</a><br>Phone: (503) 616-4493<br>Redhat Certified Engineer - RHCE #804007137224095<br>VMware Certified Professional - VCP #18529<br>