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-3559 Lustre <p>With Lustre 2.1, I format an MGS with the follwing command:</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java">mkfs.lustre --reformat --quiet --fsname=migrate --mgs --mkfsoptions=<span class="code-quote">"-m 0"</span> --device-size=204800 /root/mgt</pre> </div></div> <p>Before starting this MGS, tunefs.lustre gives:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># tunefs.lustre --print /root/mgt checking for existing Lustre data: found CONFIGS/mountdata Reading CONFIGS/mountdata Read previous values: Target: MGS Index: unassigned Lustre FS: migrate Mount type: ldiskfs Flags: 0x74 (MGS needs_index first_time update ) Persistent mount opts: user_xattr,errors=remount-ro Parameters: Permanent disk data: Target: MGS Index: unassigned Lustre FS: migrate Mount type: ldiskfs Flags: 0x74 (MGS needs_index first_time update ) Persistent mount opts: user_xattr,errors=remount-ro Parameters: </pre> </div></div> <p>Still with Lustre 2.1, I successfully start this MGS, and afterwards tunefs.lustre gives:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># tunefs.lustre --print /root/mgt checking for existing Lustre data: found CONFIGS/mountdata Reading CONFIGS/mountdata Read previous values: Target: MGS Index: unassigned Lustre FS: migrate Mount type: ldiskfs Flags: 0x74 (MGS needs_index first_time update ) Persistent mount opts: user_xattr,errors=remount-ro Parameters: Permanent disk data: Target: MGS Index: unassigned Lustre FS: migrate Mount type: ldiskfs Flags: 0x74 (MGS needs_index first_time update ) Persistent mount opts: user_xattr,errors=remount-ro Parameters: </pre> </div></div> <p>Then I update to Lustre 2.4 on my node, and when I try to start this MGS I get:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># mount -t lustre -o loop /root/mgt /mnt/migrate/mgt mount.lustre.orig: /dev/loop0 has no index assigned (probably formatted with old mkfs) </pre> </div></div> <p>In Lustre 2.4, it seems mount.lustre requires every target, including MGT, to have an index. But with Lustre 2.1, MGTs can be formatted without specifying an index, and this is the way all our customers did. So if these customers migrate to Lustre 2.4, they will not be able to start their MGS.</p> <p>I will propose a patch for mount.lustre in Lustre 2.4 to address this issue.</p> <p>Sebastien.</p> LU-3559

MGS formatted with Lustre 2.1 cannot be started with Lustre 2.4

Bug Blocker Resolved Fixed Bruno Faccini Sebastien Buisson Fri, 5 Jul 2013 11:30:06 +0000 Mon, 12 Aug 2013 18:21:26 +0000 Mon, 12 Aug 2013 18:21:26 +0000 Lustre 2.4.0 Lustre 2.5.0 Lustre 2.4.1 Lustre 2.5.0 0 7 <p>The patch is at:<br/> <a href="http://review.whamcloud.com/6904" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/6904</a></p> <p>TIA,<br/> Sebastien.</p> <p>Looks like a duplicate of <a href="https://jira.whamcloud.com/browse/LU-2022" title="MGS fails to mount due to &quot;has no index assigned (probably formatted with old mkfs&quot; error" class="issue-link" data-issue-key="LU-2022"><del>LU-2022</del></a> at first reading, will verify this definitely and update soon.</p> <p>Yes probably the issue described in <a href="https://jira.whamcloud.com/browse/LU-2022" title="MGS fails to mount due to &quot;has no index assigned (probably formatted with old mkfs&quot; error" class="issue-link" data-issue-key="LU-2022"><del>LU-2022</del></a> is the same, but the solution that was adopted at that time (patch in mkfs.lustre) is useless in case of 'real' migration from 2.1 to 2.4, because we cannot afford reformatting the MGS on production clusters.</p> <p>That's what I am trying to fully understand and why not advocate !! BTW, if it is the case, I think the test in your patch should better be something like :</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>if ((IS_MDT(ldd) || IS_OST(ldd)) &amp;&amp; (ldd-&gt;ldd_flags &amp; LDD_F_NEED_INDEX)) </pre> </div></div> <p>instead of only :</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>if (!IS_MGS(ldd) &amp;&amp; (ldd-&gt;ldd_flags &amp; LDD_F_NEED_INDEX)) </pre> </div></div> <p>to handle joint MGT/MDT case.</p> <p>You are right about the joint MGS/MDT case, I have updated my patch accordingly.</p> <p>Concerning you other question, I can tell for sure that without this patch I simply cannot start my MGT <img class="emoticon" src="https://jira.whamcloud.com/images/icons/emoticons/sad.png" height="16" width="16" align="absmiddle" alt="" border="0"/></p> <p>Sebastien.</p> <p>Ok, so seems that original (and identical to your!) fix for <a href="https://jira.whamcloud.com/browse/LU-2022" title="MGS fails to mount due to &quot;has no index assigned (probably formatted with old mkfs&quot; error" class="issue-link" data-issue-key="LU-2022"><del>LU-2022</del></a> has been diverted for some reason (others missing index issues, DNE, ...) leading to this interop bug to be left not fixed.</p> <p>So now I will ask for some other reviewers. And re-trigger the change to auto-tests since it failed due to some known and currently worked-on test problem (LU-3560).</p> <p>On the other hand, and in case of absolute need without the fix in, you can allow your 2.1 formatted MGT to be mounted by/after :</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre> _ "mount -t [ldiskfs,zfs]" your MGT stand-alone device _ binary edit underlying "CONFIGS/mountdata" file _ change the unset/"ffff" MGT index value, at offset 0x18/24 in file, to "0000" </pre> </div></div> <p>Seems that original fix for <a href="https://jira.whamcloud.com/browse/LU-2022" title="MGS fails to mount due to &quot;has no index assigned (probably formatted with old mkfs&quot; error" class="issue-link" data-issue-key="LU-2022"><del>LU-2022</del></a> has been lost in its last change patch-set.</p> <p>Gosh, the 2.1 MGT manipulation is not that easy...<br/> This is why I would like to have the patch in the 2.4 release we will roll out to our customers <img class="emoticon" src="https://jira.whamcloud.com/images/icons/emoticons/smile.png" height="16" width="16" align="absmiddle" alt="" border="0"/>)</p> <p>Patch landed to Master. Can this ticket be closed or is more work needed?</p> <p>Patch landed to master, so closing ticket. If more work is needed, let me know and I will reopen.</p> <p>Hi,</p> <p>I would like this ticket to be reopened as I have just pushed a b2_4 version of the patch:<br/> <a href="http://review.whamcloud.com/7176" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/7176</a></p> <p>Thanks,<br/> Sebastien.</p> <p>Reopened for b2_4 patch</p> <p>Added Li Wei and myself as reviewers.</p> <p>Landed for 2.4.1 and 2.5</p> Related LU-2022 Development Rank 1|hzvuof: Rank (Obsolete) 8964 Severity