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On 10/11/2018 10:59 AM, Lars Ellenberg wrote:<br>
<blockquote type="cite" cite="mid:20181011085928.GB5528@soda.linbit">
<pre wrap="">On Wed, Oct 10, 2018 at 11:52:34AM +0000, Garrido, Cristina wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hello,
I have two drbd devices configured on my cluster. On both nodes the status shows "blocked:lower" although everything seems to be fine. We have conducted IO tests on the physical devices and on the drbd devices with good results. Do you know why this message is shown and how to debug it?
The message from status command:
xxxx:/dev/mapper # drbdsetup status --verbose --statistics
ASCS node-id:1 role:Primary suspended:no
write-ordering:flush
volume:0 minor:0 disk:UpToDate
size:10452636 read:3247 written:8185665 al-writes:53 bm-writes:0 upper-pending:0 lower-pending:0 al-suspended:no blocked:lower
</pre>
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<pre wrap="">
"blocked:lower" means that the in-kernel API for querying block
device info congestion reported "congestion" for the backing device.
Why it did that, and whether that was actually the case, and what
that actually means is very much dependend on that backing device,
and how it "felt" at the time of that status output.
</pre>
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<span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Thanks
Lars,</span>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Do
you know how DRBD asks kernel about congestion information?
Which is the system call it makes?</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">We
want to know why is marking it as "blocked:lower", because we
are making heavy performance test and seems that there is no
problem at disk or network level. We think that DRBD/kernel is
not getting the correct information from the system.<br>
</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Best
regards,</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">
</span><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Victor</span></p>
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