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-6544 Lustre <p>Running <tt>mkfs.lustre --stripe-count-hint=N</tt> should tune the ldiskfs inode size to allow files with N stripes to fit the <tt>lov</tt> layout xattr into the inode rather than storing it in an external xattr block (which reduces performance and significantly increases the space used per file on the MDT). However, I think that with newer xattrs such as <tt>lma</tt> may not be taken into account in the default stripe calculations.</p> LU-6544

Improve mkfs.lustre --stripe-count-hint inode size calculation for ldiskfs

Bug Minor Resolved Fixed Emoly Liu Andreas Dilger easy Wed, 29 Apr 2015 14:36:38 +0000 Thu, 12 May 2016 18:02:41 +0000 Mon, 3 Aug 2015 15:15:02 +0000 Lustre 2.5.3 Lustre 2.8.0 Lustre 2.8.0 0 5 <p>Andreas, the current inode_size calculation is shown in the following:</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java"> /* Inode size (<span class="code-keyword">for</span> extended attributes). The LOV EA size is * 32 (EA hdr) + 32 (lov_mds_md) + stripes * 24 (lov_ost_data), * and we want some margin above that <span class="code-keyword">for</span> ACLs, other EAs... */ <span class="code-keyword">if</span> (strstr(mop-&gt;mo_mkfsopts, <span class="code-quote">"-I"</span>) == NULL) { <span class="code-keyword">if</span> (IS_MDT(&amp;mop-&gt;mo_ldd)) { <span class="code-keyword">if</span> (mop-&gt;mo_stripe_count &gt; 72) inode_size = 512; <span class="code-comment">/* bz 7241 */</span> <span class="code-comment">/* see also <span class="code-quote">"-i"</span> below <span class="code-keyword">for</span> EA blocks */</span> <span class="code-keyword">else</span> <span class="code-keyword">if</span> (mop-&gt;mo_stripe_count &gt; 32) inode_size = 2048; <span class="code-keyword">else</span> <span class="code-keyword">if</span> (mop-&gt;mo_stripe_count &gt; 10) inode_size = 1024; <span class="code-keyword">else</span> inode_size = 512; </pre> </div></div> <p>If I understand the new requirement right, no matter what stripe_count=N the user sets, we should fit lma and all current xattrs into the inode size. The the calculation looks like</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>156(ldiskfs_inode_size) + 24(lma) + 32(lov EA hdr) + 32 (lov_mds_md) + 24(lov_ost_data) * N &lt;= 512*2^m {m=0,1,2,3} </pre> </div></div> <p>And m can't be bigger than 3 (at this situation inode size will be 4096bytes), and the biggest value of N is 160, right?</p> <p>It looks like the previous limits were leaving a small amount of free space at each step (about 12 bytes), but it would be better to reduce the limits to 8, 30, 72 so there is a small amount of space reserved for other xattrs (ACL, etc) in the inode.</p> <p>Emoly Liu (emoly.liu@intel.com) uploaded a new patch: <a href="http://review.whamcloud.com/15643" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/15643</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-6544" title="Improve mkfs.lustre --stripe-count-hint inode size calculation for ldiskfs" class="issue-link" data-issue-key="LU-6544"><del>LU-6544</del></a> mkfs: Reduce mkfs.lustre --stripe-count-hint limits<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: 0e2e2ede4eaba5aa66c2436e39c713aa8a95d0c5</p> <p>Oleg Drokin (oleg.drokin@intel.com) merged in patch <a href="http://review.whamcloud.com/15643/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/15643/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-6544" title="Improve mkfs.lustre --stripe-count-hint inode size calculation for ldiskfs" class="issue-link" data-issue-key="LU-6544"><del>LU-6544</del></a> mkfs: Improve MDT inode size calculation<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 71b3cc3315114b2101bc32707fa66740279fff54</p> <p>Landed for 2.8</p> Related Development Rank 1|hzxc4n: Rank (Obsolete) 9223372036854775807 Severity