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Hi Dominic,</div>
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If health_check returns an error, there is something bad.</div>
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If health_check returns healthy, run more checks.</div>
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This is more like required, but not sufficient.</div>
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It catches errors reported by Lustre targets, but that's all. </div>
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Aurlien</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>De :</b> lustre-discuss <lustre-discuss-bounces@lists.lustre.org> de la part de Dominic Sloan-Murphy via lustre-discuss <lustre-discuss@lists.lustre.org><br>
<b>Envoy :</b> jeudi 11 juin 2026 15:21<br>
<b> :</b> lustre-discuss@lists.lustre.org <lustre-discuss@lists.lustre.org><br>
<b>Objet :</b> [lustre-discuss] Correct use of "lctl get_param health_check"</font>
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<div>Hi all,</div>
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<div>Would you be able to advise on the correct use of the "lctl get_param health_check" command from <a href="https://wiki.lustre.org/Lustre_Health_Checks">https://wiki.lustre.org/Lustre_Health_Checks</a> and under which circumstances it reports errors?</div>
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<div>I've found it always returns "healthy", even when I intentionally break my test setup. For example, removing Lustre mounts:</div>
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<div>root@lustre-build:~# mount -t lustre mytestpool/mgsmdt /mnt/mgs_mdt<br>
root@lustre-build:~# mount -t lustre ostpool/ost1 /mnt/ost<br>
root@lustre-build:~# lctl get_param health_check<br>
health_check=healthy<br>
root@lustre-build:~# umount /mnt/ost<br>
root@lustre-build:~# lctl get_param health_check<br>
health_check=healthy</div>
<div>root@lustre-build:~# umount /mnt/mgs_mdt</div>
<div>root@lustre-build:~# lctl get_param health_check<br>
health_check=healthy</div>
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<div>My setup is a single Ubuntu 24.04 VM with Lustre 2.17 built from source. The Lustre file system was created with:</div>
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<div>root@lustre-build:~# truncate -s 5G /root/mgs_mdt.img<br>
root@lustre-build:~# truncate -s 10G /root/ost.img<br>
root@lustre-build:~# mkfs.lustre --mgs --mdt --backfstype=zfs --fsname=mytestfs --index=0 mytestpool/mgsmdt /root/mgs_mdt.img<br>
root@lustre-build:~# MGS_IP=$(hostname -I | awk '{print $1}')<br>
root@lustre-build:~# mkfs.lustre --ost --backfstype=zfs --fsname=mytestfs --mgsnode=${MGS_IP}@tcp0 --index=0 ostpool/ost1 /root/ost.img</div>
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<div>Regards,</div>
<div>Dominic</div>
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Dominic Sloan-Murphy</p>
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canonical.com</p>
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We are hiring</p>
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