https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-14058 Lustre <p>Patch <a href="https://review.whamcloud.com/37759" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/37759</a> "<a href="https://jira.whamcloud.com/browse/LU-12506" title="Client unable to mount filesystem with very large number of MDTs" class="issue-link" data-issue-key="LU-12506"><del>LU-12506</del></a> changelog: support large number of MDT" allows clients to mount file systems with large numbers of MDTs. We need to create a, probably conf-sanity, test(s) that creates file systems with 16 and 32 MDTs and confirms that a client can mount this file system. The basic mount is a required test. Other testing with a large number of MDTs should be listed in this ticket.</p> LU-14058

Create tests for large number of MDTs

Improvement Minor Reopened Unresolved Sarah Liu James Nunez failing_tests tests Wed, 21 Oct 2020 15:55:37 +0000 Tue, 20 Sep 2022 14:24:04 +0000 Lustre 2.14.0 Lustre 2.16.0 0 8 <p>According to the commit message, the patch fixes the case where MDTs &gt; 64.  So It would be really good to have tests for 16 or 32 MDTs, but your mount test should have &gt;64 MDTs.</p> <p>this probably makes sense to do as part of conf-sanity and since out VMs have relatively little memory we might not be able to run 32-64 MDTs on a single node so perhaps the test would need to spread out MDTs (off loopback mounted storage in tmp perhaps) across multiple nodes</p> <p>confirm, you need &gt; 64 MDT to be sure.</p> <p>You can trip the max in /proc/misc with fewer MDTs as there are ~18 devices created by linux. This  number vary from system to system. Lustre creates two devices (obd,lnet) common for all lustre mounts in /proc/misc besides changelog devices changelog-&lt;fsname&gt;-MDT00NN (one per MDT).</p> <p>Probably Nmdt &gt; 64-(18+2), that is  Nmdt &gt; 44 will be enough but you may want to use &gt;64 to be sure.</p> <p>Note,</p> <ul> <li>the total MDT count is not necessarily for the same FS, it is total limit on number of entries in /proc/misc . You can mount two FS with 40 MDT each on the same client.</li> <li>mounting the same fs multiple times on the same client does not trigger the error (creates extra entries in /proc/misc)</li> </ul> <p>Andreas Dilger (adilger@whamcloud.com) uploaded a new patch: <a href="https://review.whamcloud.com/41485" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/41485</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-14058" title="Create tests for large number of MDTs" class="issue-link" data-issue-key="LU-14058">LU-14058</a> tests: handle more MDTs in sanity.sh<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 3<br/> Commit: 5d146e9452e3d6875fd674cd168595557f331ed5</p> <p>Oleg Drokin (green@whamcloud.com) merged in patch <a href="https://review.whamcloud.com/41485/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/41485/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-14058" title="Create tests for large number of MDTs" class="issue-link" data-issue-key="LU-14058">LU-14058</a> tests: handle more MDTs in sanity.sh<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 173bccd140adf69ce08c20810a69e783c8c12595</p> <p>Landed for 2.15</p> <p>There is still an unlanded patch for this ticket (it was originally pushed under <a href="https://jira.whamcloud.com/browse/LU-12506" title="Client unable to mount filesystem with very large number of MDTs" class="issue-link" data-issue-key="LU-12506"><del>LU-12506</del></a> so didn't show up here):</p> <p>Andreas Dilger (adilger@whamcloud.com) uploaded a new patch: <a href="https://review.whamcloud.com/38058" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/38058</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-14058" title="Create tests for large number of MDTs" class="issue-link" data-issue-key="LU-14058">LU-14058</a> tests: clean up MDT name generation<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: 2f8cc17c0f13cb805e4905d8e10f8d4536f0efce</p> <p>"Wei Liu &lt;sarah@whamcloud.com&gt;" uploaded a new patch: <a href="https://review.whamcloud.com/46268" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/46268</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-14058" title="Create tests for large number of MDTs" class="issue-link" data-issue-key="LU-14058">LU-14058</a> tests: run conf-sanity with 16 MDTs<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: bed894f273c56b743188a9ae7d1a259072f99026</p> Related LU-12506 Development Rank 1|i01cwf: Rank (Obsolete) 9223372036854775807