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Dong, Qiu Jian
86fb05065f
Reviewed-by: Eotvos, Oliver <oliver.eotvos@t-systems.com> Co-authored-by: Dong, Qiu Jian <qiujiandong1@huawei.com> Co-committed-by: Dong, Qiu Jian <qiujiandong1@huawei.com>
24 lines
2.5 KiB
HTML
24 lines
2.5 KiB
HTML
<a name="cce_faq_00296"></a><a name="cce_faq_00296"></a>
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<h1 class="topictitle1">What Should I Do If I/O Suspension Occasionally Occurs When SCSI EVS Disks Are Used?</h1>
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<div id="body1606203320690"><div class="section" id="cce_faq_00296__section1644834313614"><h4 class="sectiontitle">Symptom</h4><p id="cce_faq_00296__p19826120163312">When SCSI EVS disks are used and containers are created and deleted on a CentOS node, the disks are frequently mounted and unmounted. The read/write rate of the system disk may instantaneously surge. As a result, the system is suspended, affecting the normal node running.</p>
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<p id="cce_faq_00296__p117111015513">When this problem occurs, the following information is displayed in the dmesg log:</p>
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<pre class="screen" id="cce_faq_00296__screen235813212515">Attached SCSI disk
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task jdb2/xxx blocked for more than 120 seconds.</pre>
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<p id="cce_faq_00296__p41717132419">Example:</p>
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<p id="cce_faq_00296__p761119299581"><span><img id="cce_faq_00296__image1689283414594" src="en-us_image_0000001897904393.png"></span></p>
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</div>
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<div class="section" id="cce_faq_00296__section1217032912611"><h4 class="sectiontitle">Possible Cause</h4><p id="cce_faq_00296__p739312083317">After a PCI device is hot added to BUS 0, the Linux OS kernel will traverse all the PCI bridges mounted to BUS 0 for multiple times, and these PCI bridges cannot work properly during this period. During this period, if the PCI bridge used by the device is updated, due to a kernel defect, the device considers that the PCI bridge is abnormal, and the device enters a fault mode and cannot work normally. If the front end is writing data into the PCI configuration space for the back end to process disk I/Os, the write operation may be deleted. As a result, the back end cannot receive notifications to process new requests on the I/O ring. Finally, the front-end I/O suspension occurs.</p>
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</div>
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<div class="section" id="cce_faq_00296__section122155314507"><h4 class="sectiontitle">Impact</h4><p id="cce_faq_00296__p18162155520501">CentOS Linux kernels of versions earlier than 3.10.0-1127.el7 are affected.</p>
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</div>
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<div class="section" id="cce_faq_00296__en-us_topic_0176582190_section1446470135915"><h4 class="sectiontitle">Solution</h4><p id="cce_faq_00296__p7399162013519">Upgrade the kernel to a later version <strong id="cce_faq_00296__b1353925955413">by resetting the node</strong>.</p>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="cce_faq_00281.html">Node Running</a></div>
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</div>
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</div>
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