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-10665 Lustre <p>Append test for DoM files shows bad results after some changes in LOV/LOD. It causes OST component initialization with OST objects creation. That has bad effect on append itself but also makes impossible other optimizations for DoM file even when its size is still small.</p> <p>DOM files append:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>## ./smalliomany -a /mnt/lustre/dp_dom/file- 16384 300 ## 2018-01-28 19:04:36: START total: append 33758741 bytes in 94 seconds: 359135.54 bytes/second ----- MDC RPCs: 163800 ----- OSC RPCs: 16392 &lt;--- that is wrong behavior </pre> </div></div> LU-10665

DoM: append to file causes OST component initialization

Technical task LU-10176 Major Resolved Duplicate Mikhail Pershin Mikhail Pershin DoM2 Wed, 14 Feb 2018 15:11:40 +0000 Tue, 7 Apr 2020 18:23:16 +0000 Fri, 9 Mar 2018 01:12:49 +0000 0 4 <p>this issue affects any file with PFL layout but hurts DOM files more than other, the problem with append is a range which is set to [0, EOF) and LOV<br/> start initializing all components in the range even when append size is very small. To use correct range the file size is needed but it can be trusted only when lock is taken which is done after IO initialization. One possible way to fix this for PFL files is to use only last initialized component end as append end and restart IO if needed later (when file size is known, we have real range and it is clear that next component must be initialized).</p> <p>This may be fixed by patch <a href="https://review.whamcloud.com/31411" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/31411</a> "<tt><a href="https://jira.whamcloud.com/browse/LU-9341" title="PFL: append should not instantiate full layout" class="issue-link" data-issue-key="LU-9341"><del>LU-9341</del></a> llite: don't instantiate full layout on append</tt>", which is a general problem for composite files, not just DoM.</p> Duplicate LU-9341 Related LU-13420 Development Rank 1|hzzstr: Rank (Obsolete) 9223372036854775807