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/LUDOC-261 Lustre Documentation <p>The Lustre manual mentions a phase 1 and a phase 2 of the LFSCK namespace and layout checks, but it doesn't explain what the phases mean. The documentation should explain what the phases mean so that the LFSCK user can understand the output of the LFSCK status interface.</p> LUDOC-261

LFSCK namespace and layout check phases need explanation

Bug Minor Closed Fixed Richard Henwood Ryan Haasken Tue, 11 Nov 2014 16:12:07 +0000 Fri, 19 Feb 2016 22:13:13 +0000 Fri, 19 Feb 2016 22:13:13 +0000 0 2 <p>From Fan Yong on <a href="https://jira.whamcloud.com/browse/LUDOC-244" title="LFSCK Adjustment Interface documentation is inconsistent" class="issue-link" data-issue-key="LUDOC-244"><del>LUDOC-244</del></a>:</p> <blockquote> <p>Currently, LFSCK use two phases scanning to guarantee all the inconsistency can be handled completely and efficiently.</p> <p>1) The first-stage scanning<br/> There is a LFSCK main engine on every MDT/OST that involves the LFSCK. During the first-stage scanning, each LFSCK main engine scans its local device via low layer object-table based iteration that uses linear scanning method and guarantees that all the objects related with this server (MDT or OST) will be checked. But sometimes, the LFSCK cannot know whether the object is inconsistency or cannot know how to repair the inconsistency until the first-stage scanning finished. Then the LFSCK needs the second-stage scanning.</p> <p>2) The second-stage scanning<br/> During the first stage-scaninng, some uncertain objects will be recorded, depends on the LFSCK type.</p> <p>2.1) For namespace LFSCK, the object will multiple hard-links, or with multiple linkEA entries, or with remote parent, and so on, will be recorded in the namespace LFSCK tracing file. And then, in the second-stage scanning, the namespace LFSCK will scan the objects in the namespace LFSCK tracing file in turn and handle the uncertain inconsistency.</p> <p>2.2) For layout LFSCK, the OST-objects that are not referenced by any MDT-object are recorded in a bitmap. When the LFSCK moves to the second-stage scanning, the OST-objects in such bitmap will be re-scanned to check whether they are really orphans or not.</p></blockquote> <p>I think it would be appropriate to describe these phases in the "Description" sections of the "LFSCK status of namespace via procfs" and "LFSCK status of layout via procfs" sections.</p> <p><a href="http://review.whamcloud.com/#/c/12676/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/12676/</a></p> <p>Richard Henwood (richard.henwood@intel.com) merged in patch <a href="http://review.whamcloud.com/12676/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/12676/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LUDOC-261" title="LFSCK namespace and layout check phases need explanation" class="issue-link" data-issue-key="LUDOC-261"><del>LUDOC-261</del></a> lfsck: Describe phases of namespace/layout LFSCK<br/> Project: doc/manual<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 7406eeae7c8acb7598d59d28d0183657005fc6bd</p> <p>This can be closed now. Thanks, Richard.</p> Development Rank 1|hzx0pr: Rank (Obsolete) 16491 Severity