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    <p>Thanks for the fast reply! If I understood correctly, it is
      currently not possible to use the changelog feature together with
      the snapshot feature, right? <br>
    </p>
    <p>Is there already a LU-Ticket about that?</p>
    <p>Cheers,<br>
      Robert<br>
    </p>
    <br>
    <div class="moz-cite-prefix">On 09/10/2018 02:57 PM, Yong, Fan
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:7FB055E0B36B6F4EB93E637E0640A56FCC040CC4@FMSMSX125.amr.corp.intel.com">
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        <p class="MsoNormal"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
            lang="EN-US">It is suspected that there were some llog to be
            handled when the snapshot was making Then when mount-up such
            snapshot, some conditions trigger the llog
            cleanup/modification automatically. So it is not related
            with your actions when mount the snapshot. Since we cannot
            control the system status when making the snapshot, then we
            have to skip llog related cleanup/modification against the
            snapshot when mount the snapshot. Such “skip” related logic
            is just what we need.<o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
            lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
            lang="EN-US">Cheers,<o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
            lang="EN-US">Nasf<o:p></o:p></span></p>
        <div>
          <div style="border:none;border-top:solid #E1E1E1
            1.0pt;padding:3.0pt 0cm 0cm 0cm">
            <p class="MsoNormal"
              style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><b><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"
                  lang="EN-US">From:</span></b><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"
                lang="EN-US"> lustre-discuss
                [<a class="moz-txt-link-freetext" href="mailto:lustre-discuss-bounces@lists.lustre.org">mailto:lustre-discuss-bounces@lists.lustre.org</a>] <b>On
                  Behalf Of </b>
                Robert Redl<br>
                <b>Sent:</b> Saturday, September 8, 2018 9:04 PM<br>
                <b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:lustre-discuss@lists.lustre.org">lustre-discuss@lists.lustre.org</a><br>
                <b>Subject:</b> Re: [lustre-discuss] Lustre/ZFS
                snapshots mount error<o:p></o:p></span></p>
          </div>
        </div>
        <p class="MsoNormal"
          style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US"><o:p> </o:p></span></p>
        <p style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US">Dear All,
            <o:p></o:p></span></p>
        <p style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US">we have a similar setup with Lustre on ZFS and
            we make regular use of snapshots for the purpose of backups
            (backups on tape use snapshots as source). We would like to
            use robinhood in future and the question is now how to do
            it. <o:p></o:p></span></p>
        <p style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US">Would it be a workaround to disable the
            robinhood daemon temporary during the mount process?<br>
            Does the problem only occur when changelogs are consumed
            during the process of mounting a snapshot? Or is it also a
            problem when changelogs are consumed while the snapshot
            remains mounted (which is for us typically several hours)?
            <br>
            Is there already an LU-ticket about this issue?<o:p></o:p></span></p>
        <p style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US">Thanks!<br>
            Robert<o:p></o:p></span></p>
        <p class="MsoNormal"
style="mso-margin-top-alt:0cm;margin-right:0cm;margin-bottom:12.0pt;margin-left:21.0pt;mso-margin-top-alt:0cm;mso-para-margin-right:0cm;mso-para-margin-bottom:12.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US">-- <br>
            Dr. Robert Redl<br>
            Scientific Programmer, "Waves to Weather" (SFB/TRR165)<br>
            Meteorologisches Institut<br>
            Ludwig-Maximilians-Universität München<br>
            Theresienstr. 37, 80333 München, Germany<o:p></o:p></span></p>
        <div>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
              lang="EN-US">Am 03.09.2018 um 08:16 schrieb Yong, Fan:<o:p></o:p></span></p>
        </div>
        <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
              lang="EN-US">I would say that it is not your operations
              order caused trouble. Instead, it is related with the
              snapshot mount logic. As mentioned in former reply, we
              need some patch for the llog logic to avoid modifying llog
              under snapshot mode.</span><span lang="EN-US"><o:p></o:p></span></p>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
              lang="EN-US"> </span><span lang="EN-US"><o:p></o:p></span></p>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
              lang="EN-US"> </span><span lang="EN-US"><o:p></o:p></span></p>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
              lang="EN-US">--</span><span lang="EN-US"><o:p></o:p></span></p>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
              lang="EN-US">Cheers,</span><span lang="EN-US"><o:p></o:p></span></p>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
style="font-size:10.5pt;font-family:"Calibri",sans-serif;color:#1F497D"
              lang="EN-US">Nasf</span><span lang="EN-US"><o:p></o:p></span></p>
          <div>
            <div style="border:none;border-top:solid #E1E1E1
              1.0pt;padding:3.0pt 0cm 0cm 0cm">
              <p class="MsoNormal"
                style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><b><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif"
                    lang="EN-US">From:</span></b><span
                  style="font-size:11.0pt;font-family:"Calibri",sans-serif"
                  lang="EN-US"> Kirk, Benjamin (JSC-EG311) [<a
                    href="mailto:benjamin.kirk@nasa.gov"
                    moz-do-not-send="true">mailto:benjamin.kirk@nasa.gov</a>]
                  <br>
                  <b>Sent:</b> Tuesday, August 28, 2018 7:53 PM<br>
                  <b>To:</b> <a
                    href="mailto:lustre-discuss@lists.lustre.org"
                    moz-do-not-send="true">lustre-discuss@lists.lustre.org</a><br>
                  <b>Cc:</b> Andreas Dilger <a
                    href="mailto:adilger@whamcloud.com"
                    moz-do-not-send="true"><adilger@whamcloud.com></a>;
                  Yong, Fan
                  <a href="mailto:fan.yong@intel.com"
                    moz-do-not-send="true"><fan.yong@intel.com></a><br>
                  <b>Subject:</b> Re: [lustre-discuss] Lustre/ZFS
                  snapshots mount error</span><span lang="EN-US"><o:p></o:p></span></p>
            </div>
          </div>
          <p class="MsoNormal"
            style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
              lang="EN-US"> <o:p></o:p></span></p>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">The MDS situation is very basic:
                active/passive mds0/mds1 for both fas & fsB.  fsA
                has the combined msg/mdt in a single zfs filesystem, and
                fsB has its own mdt in a separate zfs filesystem.  mds0
                is primary for all.<o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US"> <o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">fsA & fsB DO both have changelogs
                enabled to feed robinhood databases.<o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US"> <o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">What</span>’<span lang="EN-US">s the
                recommended procedure here we should follow before
                mounting the snapshots?<o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US"> <o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">1) disable changelogs on the active mdt</span>’<span
                lang="EN-US">s (this will compromise robinhood,
                requiring a rescan</span>…<span lang="EN-US">), or  <o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">2) temporarily halt changelog consumption /
                cleanup (e.g. stop robinhood in our case) and then mount
                the snapshot?<o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US"> <o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">Thanks for the help!
                <o:p></o:p></span></p>
            <div>
              <p class="MsoNormal"
                style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                  lang="EN-US"> <o:p></o:p></span></p>
            </div>
          </div>
          <div>
            <p class="MsoNormal"
              style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                lang="EN-US">--<o:p></o:p></span></p>
            <div>
              <div>
                <div>
                  <div>
                    <p class="MsoNormal"
                      style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                        lang="EN-US">Benjamin S. Kirk, Ph.D.<o:p></o:p></span></p>
                  </div>
                  <div>
                    <p class="MsoNormal"
                      style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                        lang="EN-US">NASA Lyndon B. Johnson Space Center<o:p></o:p></span></p>
                  </div>
                  <div>
                    <p class="MsoNormal"
                      style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                        lang="EN-US">Acting Chief, Aeroscience &
                        Flight Mechanics Division<o:p></o:p></span></p>
                  </div>
                  <div>
                    <p class="MsoNormal"
                      style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                        lang="EN-US"> <o:p></o:p></span></p>
                  </div>
                </div>
              </div>
              <div>
                <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
                  <div>
                    <p class="MsoNormal"
                      style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                        lang="EN-US">On Aug 27, 2018, at 7:33 PM, Yong,
                        Fan <<a href="mailto:fan.yong@intel.com"
                          moz-do-not-send="true">fan.yong@intel.com</a>>
                        wrote:<o:p></o:p></span></p>
                  </div>
                  <p class="MsoNormal"
                    style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                      lang="EN-US"> <o:p></o:p></span></p>
                  <div>
                    <div>
                      <p class="MsoNormal"
                        style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                          lang="EN-US">According to the stack trace,
                          someone was trying to cleanup old empty llogs
                          during mount the snapshot. We do NOT allow any
                          modification during mount snapshot; otherwise,
                          it will trigger ZFS backend BUG(). That is why
                          we add LASSERT() when start the transaction.
                          One possible solution is that, we can add some
                          check in the llog logic to avoid modifying
                          llog under snapshot mode.<br>
                          <br>
                          <br>
                          --<br>
                          Cheers,<br>
                          Nasf<br>
                          <br>
                          -----Original Message-----<br>
                          From: lustre-discuss [<a
                            href="mailto:lustre-discuss-bounces@lists.lustre.org"
                            moz-do-not-send="true">mailto:lustre-discuss-bounces@lists.lustre.org</a>]
                          On Behalf Of Andreas Dilger<br>
                          Sent: Tuesday, August 28, 2018 5:57 AM<br>
                          To: Kirk, Benjamin (JSC-EG311) <<a
                            href="mailto:benjamin.kirk@nasa.gov"
                            moz-do-not-send="true">benjamin.kirk@nasa.gov</a>><br>
                          Cc: <a
                            href="mailto:lustre-discuss@lists.lustre.org"
                            moz-do-not-send="true">lustre-discuss@lists.lustre.org</a><br>
                          Subject: Re: [lustre-discuss] Lustre/ZFS
                          snapshots mount error<br>
                          <br>
                          It's probably best to file an LU ticket for
                          this issue.<br>
                          <br>
                          It looks like there is something with the log
                          processing at mount that is trying to modify
                          the configuration files.  I'm not sure whether
                          that should be allowed or not.<br>
                          <br>
                          Does fab have the same MGS as fsA?  Does it
                          have the same MDS node as fsA?<br>
                          If it has a different MDS, you might consider
                          to give it its own MGS as well.<br>
                          That doesn't have to be a separate MGS node,
                          just a separate filesystem (ZFS fileset in the
                          same zpool) on the MDS node.<br>
                          <br>
                          Cheers, Andreas<br>
                          <br>
                          <br>
                          <br>
                          <o:p></o:p></span></p>
                      <blockquote
                        style="margin-top:5.0pt;margin-bottom:5.0pt">
                        <p class="MsoNormal"
                          style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                            lang="EN-US">On Aug 27, 2018, at 10:18,
                            Kirk, Benjamin (JSC-EG311) <<a
                              href="mailto:benjamin.kirk@nasa.gov"
                              moz-do-not-send="true">benjamin.kirk@nasa.gov</a>>
                            wrote:<br>
                            <br>
                            Hi all,<br>
                            <br>
                            We have two filesystems, fsA & fsB (eadc
                            below).  Both of which get snapshots taken
                            daily, rotated over a week.  It</span>’<span
                            lang="EN-US">s a beautiful feature we</span>’<span
                            lang="EN-US">ve been using in production
                            ever since it was introduced with 2.10.<br>
                            <br>
                            -) We</span>’<span lang="EN-US">ve got
                            Lustre/ZFS 2.10.4 on CentOS 7.5.<br>
                            -) Both fsA & fsB have changelogs
                            active.<br>
                            -) fsA has combined mgt/mdt on a single ZFS
                            filesystem.<br>
                            -) fsB has a single mdt on a single ZFS
                            filesystem.<br>
                            -) for fsA, I have no issues mounting any of
                            the snapshots via lctl.<br>
                            -) for fsB, I can mount the most three
                            recent snapshots, then encounter errors:<br>
                            <br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount
                            -F eadc -n eadc_AutoSS-Mon <br>
                            mounted the snapshot eadc_AutoSS-Mon with
                            fsname 3d40bbc<br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount
                            -F eadc -n <br>
                            eadc_AutoSS-Mon<br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount
                            -F eadc -n eadc_AutoSS-Sun <br>
                            mounted the snapshot eadc_AutoSS-Sun with
                            fsname 584c07a<br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount
                            -F eadc -n <br>
                            eadc_AutoSS-Sun<br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount
                            -F eadc -n eadc_AutoSS-Sat <br>
                            mounted the snapshot eadc_AutoSS-Sat with
                            fsname 4e646fe<br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount
                            -F eadc -n <br>
                            eadc_AutoSS-Sat<br>
                            [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount
                            -F eadc -n eadc_AutoSS-Fri<br>
                            mount.lustre: mount
                            metadata/meta-eadc@eadc_AutoSS-Fri at <br>
                            /mnt/eadc_AutoSS-Fri_MDT0000 failed:
                            Read-only file system Can't mount <br>
                            the snapshot eadc_AutoSS-Fri: Read-only file
                            system<br>
                            <br>
                            The relevant bits from dmesg are<br>
                            [1353434.417762] Lustre: 3d40bbc-MDT0000:
                            set dev_rdonly on this <br>
                            device [1353434.417765] Lustre: Skipped 3
                            previous similar messages <br>
                            [1353434.649480] Lustre: 3d40bbc-MDT0000:
                            Imperative Recovery enabled, <br>
                            recovery window shrunk from 300-900 down to
                            150-900 [1353434.649484] <br>
                            Lustre: Skipped 3 previous similar messages
                            [1353434.866228] Lustre: <br>
                            3d40bbc-MDD0000: changelog on
                            [1353434.866233] Lustre: Skipped 1 <br>
                            previous similar message [1353435.427744]
                            Lustre: 3d40bbc-MDT0000: <br>
                            Connection restored to <a
                              href="mailto:...@tcp"
                              moz-do-not-send="true">...@tcp</a> (at <a
                              href="mailto:...@tcp"
                              moz-do-not-send="true">
                              ...@tcp</a>) [1353435.427747] Lustre: <br>
                            Skipped 23 previous similar messages
                            [1353445.255899] Lustre: Failing <br>
                            over 3d40bbc-MDT0000 [1353445.255903]
                            Lustre: Skipped 3 previous <br>
                            similar messages [1353445.256150]
                            LustreError: 11-0: <br>
                            3d40bbc-OST0000-osc-MDT0000: operation
                            ost_disconnect to node <a
                              href="mailto:...@tcp"
                              moz-do-not-send="true">
                              ...@tcp</a> <br>
                            failed: rc = -107 [1353445.257896]
                            LustreError: Skipped 23 previous <br>
                            similar messages [1353445.353874] Lustre:
                            server umount <br>
                            3d40bbc-MDT0000 complete [1353445.353877]
                            Lustre: Skipped 3 previous <br>
                            similar messages [1353475.302224] Lustre:
                            4e646fe-MDD0000: changelog <br>
                            on [1353475.302228] Lustre: Skipped 1
                            previous similar message [1353498.964016]
                            LustreError:
                            25582:0:(osd_handler.c:341:osd_trans_create())
                            36ca26b-MDT0000-osd: someone try to start
                            transaction under readonly mode, should be
                            disabled.<br>
                            [1353498.967260] LustreError:
                            25582:0:(osd_handler.c:341:osd_trans_create())
                            Skipped 1 previous similar message<br>
                            [1353498.968829] CPU: 6 PID: 25582 Comm:
                            mount.lustre Kdump: loaded Tainted: P
                                      OE  ------------
                              3.10.0-862.6.3.el7.x86_64 #1<br>
                            [1353498.968830] Hardware name: Supermicro
                            SYS-6027TR-D71FRF/X9DRT, <br>
                            BIOS 3.2a 08/04/2015 [1353498.968832] Call
                            Trace:<br>
                            [1353498.968841]  [<ffffffffb5b0e80e>]
                            dump_stack+0x19/0x1b <br>
                            [1353498.968851]  [<ffffffffc0cbe5db>]
                            osd_trans_create+0x38b/0x3d0 <br>
                            [osd_zfs] [1353498.968876]
                             [<ffffffffc1116044>] <br>
                            llog_destroy+0x1f4/0x3f0 [obdclass]
                            [1353498.968887]  <br>
                            [<ffffffffc111f0f6>]
                            llog_cat_reverse_process_cb+0x246/0x3f0 <br>
                            [obdclass] [1353498.968897]
                             [<ffffffffc111a32c>] <br>
                            llog_reverse_process+0x38c/0xaa0 [obdclass]
                            [1353498.968910]  <br>
                            [<ffffffffc111eeb0>] ?
                            llog_cat_process_cb+0x4e0/0x4e0 [obdclass] <br>
                            [1353498.968922]  [<ffffffffc111af69>]
                            <br>
                            llog_cat_reverse_process+0x179/0x270
                            [obdclass] [1353498.968932]  <br>
                            [<ffffffffc1115585>] ?
                            llog_init_handle+0xd5/0x9a0 [obdclass] <br>
                            [1353498.968943]  [<ffffffffc1116e78>]
                            ? llog_open_create+0x78/0x320 <br>
                            [obdclass] [1353498.968949]
                             [<ffffffffc12e55f0>] ? <br>
                            mdd_root_get+0xf0/0xf0 [mdd]
                            [1353498.968954]  [<ffffffffc12ec7af>]
                            <br>
                            mdd_prepare+0x13ff/0x1c70 [mdd]
                            [1353498.968966]  [<ffffffffc166b037>]
                            <br>
                            mdt_prepare+0x57/0x3b0 [mdt]
                            [1353498.968983]  [<ffffffffc1183afd>]
                            <br>
                            server_start_targets+0x234d/0x2bd0
                            [obdclass] [1353498.968999]  <br>
                            [<ffffffffc1153500>] ?
                            class_config_dump_handler+0x7e0/0x7e0 <br>
                            [obdclass] [1353498.969012]
                             [<ffffffffc118541d>] <br>
                            server_fill_super+0x109d/0x185a [obdclass]
                            [1353498.969025]  <br>
                            [<ffffffffc115cef8>]
                            lustre_fill_super+0x328/0x950 [obdclass] <br>
                            [1353498.969038]  [<ffffffffc115cbd0>]
                            ? <br>
                            lustre_common_put_super+0x270/0x270
                            [obdclass] [1353498.969041]  <br>
                            [<ffffffffb561f3bf>]
                            mount_nodev+0x4f/0xb0 [1353498.969053]  <br>
                            [<ffffffffc1154f18>]
                            lustre_mount+0x38/0x60 [obdclass] <br>
                            [1353498.969055]  [<ffffffffb561ff3e>]
                            mount_fs+0x3e/0x1b0 [1353498.969060]
                             [<ffffffffb563d4b7>]
                            vfs_kern_mount+0x67/0x110 [1353498.969062]
                             [<ffffffffb563fadf>]
                            do_mount+0x1ef/0xce0 [1353498.969066]
                             [<ffffffffb55f7c2c>] ?
                            kmem_cache_alloc_trace+0x3c/0x200
                            [1353498.969069]  [<ffffffffb5640913>]
                            SyS_mount+0x83/0xd0 [1353498.969074]
                             [<ffffffffb5b20795>]
                            system_call_fastpath+0x1c/0x21
                            [1353498.969079] LustreError:
                            25582:0:(llog_cat.c:1027:llog_cat_reverse_process_cb())
                            36ca26b-MDD0000: fail to destroy empty log:
                            rc = -30<br>
                            [1353498.970785] CPU: 6 PID: 25582 Comm:
                            mount.lustre Kdump: loaded Tainted: P
                                      OE  ------------
                              3.10.0-862.6.3.el7.x86_64 #1<br>
                            [1353498.970786] Hardware name: Supermicro
                            SYS-6027TR-D71FRF/X9DRT, <br>
                            BIOS 3.2a 08/04/2015 [1353498.970787] Call
                            Trace:<br>
                            [1353498.970790]  [<ffffffffb5b0e80e>]
                            dump_stack+0x19/0x1b <br>
                            [1353498.970795]  [<ffffffffc0cbe5db>]
                            osd_trans_create+0x38b/0x3d0 <br>
                            [osd_zfs] [1353498.970807]
                             [<ffffffffc1117921>] <br>
                            llog_cancel_rec+0xc1/0x880 [obdclass]
                            [1353498.970817]  <br>
                            [<ffffffffc111e13b>]
                            llog_cat_cleanup+0xdb/0x380 [obdclass] <br>
                            [1353498.970827]  [<ffffffffc111f14d>]
                            <br>
                            llog_cat_reverse_process_cb+0x29d/0x3f0
                            [obdclass] [1353498.970838]  <br>
                            [<ffffffffc111a32c>]
                            llog_reverse_process+0x38c/0xaa0 [obdclass]
                            <br>
                            [1353498.970848]  [<ffffffffc111eeb0>]
                            ? <br>
                            llog_cat_process_cb+0x4e0/0x4e0 [obdclass]
                            [1353498.970858]  <br>
                            [<ffffffffc111af69>]
                            llog_cat_reverse_process+0x179/0x270
                            [obdclass] <br>
                            [1353498.970868]  [<ffffffffc1115585>]
                            ? llog_init_handle+0xd5/0x9a0 <br>
                            [obdclass] [1353498.970878]
                             [<ffffffffc1116e78>] ? <br>
                            llog_open_create+0x78/0x320 [obdclass]
                            [1353498.970883]  <br>
                            [<ffffffffc12e55f0>] ?
                            mdd_root_get+0xf0/0xf0 [mdd]
                            [1353498.970887]  <br>
                            [<ffffffffc12ec7af>]
                            mdd_prepare+0x13ff/0x1c70 [mdd]
                            [1353498.970894]  <br>
                            [<ffffffffc166b037>]
                            mdt_prepare+0x57/0x3b0 [mdt]
                            [1353498.970908]  <br>
                            [<ffffffffc1183afd>]
                            server_start_targets+0x234d/0x2bd0
                            [obdclass] <br>
                            [1353498.970924]  [<ffffffffc1153500>]
                            ? <br>
                            class_config_dump_handler+0x7e0/0x7e0
                            [obdclass] [1353498.970938]  <br>
                            [<ffffffffc118541d>]
                            server_fill_super+0x109d/0x185a [obdclass] <br>
                            [1353498.970950]  [<ffffffffc115cef8>]
                            lustre_fill_super+0x328/0x950 <br>
                            [obdclass] [1353498.970962]
                             [<ffffffffc115cbd0>] ? <br>
                            lustre_common_put_super+0x270/0x270
                            [obdclass] [1353498.970964]  <br>
                            [<ffffffffb561f3bf>]
                            mount_nodev+0x4f/0xb0 [1353498.970976]  <br>
                            [<ffffffffc1154f18>]
                            lustre_mount+0x38/0x60 [obdclass] <br>
                            [1353498.970978]  [<ffffffffb561ff3e>]
                            mount_fs+0x3e/0x1b0 <br>
                            [1353498.970980]  [<ffffffffb563d4b7>]
                            vfs_kern_mount+0x67/0x110 <br>
                            [1353498.970982]  [<ffffffffb563fadf>]
                            do_mount+0x1ef/0xce0 <br>
                            [1353498.970984]  [<ffffffffb55f7c2c>]
                            ? <br>
                            kmem_cache_alloc_trace+0x3c/0x200
                            [1353498.970986]  <br>
                            [<ffffffffb5640913>]
                            SyS_mount+0x83/0xd0 [1353498.970989]  <br>
                            [<ffffffffb5b20795>]
                            system_call_fastpath+0x1c/0x21
                            [1353498.970996] <br>
                            LustreError:
                            25582:0:(mdd_device.c:354:mdd_changelog_llog_init())
                            <br>
                            36ca26b-MDD0000: changelog init failed: rc =
                            -30 [1353498.972790] <br>
                            LustreError:
                            25582:0:(mdd_device.c:427:mdd_changelog_init())
                            <br>
                            36ca26b-MDD0000: changelog setup during init
                            failed: rc = -30 <br>
                            [1353498.974525] LustreError: <br>
                            25582:0:(mdd_device.c:1061:mdd_prepare())
                            36ca26b-MDD0000: failed to <br>
                            initialize changelog: rc = -30
                            [1353498.976229] LustreError: <br>
25582:0:(obd_mount_server.c:1879:server_fill_super()) Unable to start <br>
                            targets: -30 [1353499.072002] LustreError: <br>
25582:0:(obd_mount.c:1582:lustre_fill_super()) Unable to mount  (-30)<br>
                            <br>
                            <br>
                            I</span>’<span lang="EN-US">m hoping those
                            traces mean something to someone - any
                            ideas?<br>
                            <br>
                            Thanks!<br>
                            <br>
                            --<br>
                            Benjamin S. Kirk<br>
                            <br>
_______________________________________________<br>
                            lustre-discuss mailing list<br>
                            <a
                              href="mailto:lustre-discuss@lists.lustre.org"
                              moz-do-not-send="true">lustre-discuss@lists.lustre.org</a><br>
                            <a
                              href="http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org"
                              moz-do-not-send="true">http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org</a><o:p></o:p></span></p>
                      </blockquote>
                      <p class="MsoNormal"
style="mso-margin-top-alt:0cm;margin-right:0cm;margin-bottom:12.0pt;margin-left:42.0pt;mso-margin-top-alt:0cm;mso-para-margin-right:0cm;mso-para-margin-bottom:12.0pt;mso-para-margin-left:3.5gd"><span
                          lang="EN-US"><br>
                          Cheers, Andreas<br>
                          ---<br>
                          Andreas Dilger<br>
                          CTO Whamcloud<br>
                          <br>
                          <br>
                          <br>
                          <br>
                          <o:p></o:p></span></p>
                    </div>
                  </div>
                </blockquote>
              </div>
              <p class="MsoNormal"
                style="margin-left:42.0pt;mso-para-margin-left:3.5gd"><span
                  lang="EN-US"> <o:p></o:p></span></p>
            </div>
          </div>
          <p class="MsoNormal"
            style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
              lang="EN-US"><br>
              <br>
              <br>
              <o:p></o:p></span></p>
          <pre style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span lang="EN-US">_______________________________________________<o:p></o:p></span></pre>
          <pre style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span lang="EN-US">lustre-discuss mailing list<o:p></o:p></span></pre>
          <pre style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span lang="EN-US"><a href="mailto:lustre-discuss@lists.lustre.org" moz-do-not-send="true">lustre-discuss@lists.lustre.org</a><o:p></o:p></span></pre>
          <pre style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span lang="EN-US"><a href="http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org" moz-do-not-send="true">http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org</a><o:p></o:p></span></pre>
        </blockquote>
        <p class="MsoNormal"
          style="margin-left:21.0pt;mso-para-margin-left:1.75gd"><span
            lang="EN-US"><o:p> </o:p></span></p>
      </div>
    </blockquote>
    <br>
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