Difference between revisions of "OVH NVME atop Reporting Problem"

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  chmod +x /etc/rc.d/rc.local
  chmod +x /etc/rc.d/rc.local
   
   
  echo "# fixing messed up nvme disk usage reporting in the atop for OVH server" > /etc/rc/rc.d
  echo "# fixing messed up nvme disk usage reporting in the atop for OVH server" >> /etc/rc.d/rc.local
  echo "echo mq-deadline > /sys/block/nvme0n1/queue/scheduler" > /etc/rc/rc.d
  echo "echo mq-deadline > /sys/block/nvme0n1/queue/scheduler" >> /etc/rc.d/rc.local
  echo "echo mq-deadline > /sys/block/nvme1n1/queue/scheduler" > /etc/rc/rc.d
  echo "echo mq-deadline > /sys/block/nvme1n1/queue/scheduler" >> /etc/rc.d/rc.local
   
   
  reboot
  reboot


Make sure you actually have nvme0n1 and nvme1n1 devices on your system. Check with atop and change accordingly.
Make sure that you actually have nvme0n1 and nvme1n1 devices on your system. Check with atop and change accordingly.


After that problem is gone:
After that the problem is gone:


[[File:ovh_nvme_low.png]]
[[File:ovh_nvme_low.png]]
[[File:ovh_nvme_low_graph.png]]


<br><br>
<br><br>

Latest revision as of 14:41, 21 August 2020

Upon installation empty idle server with NVME disks reports unusual high NVME disk usage using atop command:

Ovh nvme high.png

It seems to be caused by the error in the kernel: https://github.com/Atoptool/atop/issues/47

As OVH kernel upgrade procedure is messed up, and new kernels (as of 2020-08-13) does not have a fix, a faster workaround is to set the NVMe device's I/O scheduler to 'mq-deadline' instead of the default 'none'

On Centos 7 this can be done like this:

chmod +x /etc/rc.d/rc.local

echo "# fixing messed up nvme disk usage reporting in the atop for OVH server" >> /etc/rc.d/rc.local
echo "echo mq-deadline > /sys/block/nvme0n1/queue/scheduler" >> /etc/rc.d/rc.local
echo "echo mq-deadline > /sys/block/nvme1n1/queue/scheduler" >> /etc/rc.d/rc.local

reboot

Make sure that you actually have nvme0n1 and nvme1n1 devices on your system. Check with atop and change accordingly.

After that the problem is gone:

Ovh nvme low.png

Ovh nvme low graph.png



See also