how to reinstall node in cluster Two nodes with quorum device

auranext

Active Member
Jun 5, 2018
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Hi,

Based on the documentation I understand that I need to remove qdevice before adding node to cluster.
I don t know how to do that in secure manner.
Otherwise I can restore node files like /var/lib/pve-cluster/config.db but I don t know what exact files I need to import and what the exact procedure.

thank you

maxime
 

aaron

Proxmox Staff Member
Staff member
Jun 3, 2019
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If I understand you correctly, you have currently have a 2 node cluster + qdevice?

  • In that case, first remove the qdevice: pvecm qdevice remove
  • Then check the pvecm status confirming that only 2 votes are expected at max
  • Move all guests from the node that is to be reinstalled
  • Remove the one node following the guide https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_remove_a_cluster_node
  • Make sure that there are no leftovers (/etc/pve/nodes/<old node>, in /etc/pve/priv/authorized_keys, ...)
  • reinstall the node
  • add it to the cluster
  • install qdevice packages on the reinstalled node
  • do a pvecm qdevice setup again
That way everything should work fine. Should you encounter some issues later, for example in a live migration regarding SSH keys. Run pvecm updatecerts on all nodes.

And of course, having backups of your guests, just in case, is always a good idea :)
 

auranext

Active Member
Jun 5, 2018
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thank you for this procedure.
what is worry me is if I remove the quorum device and a node, the resulting node will be isolated and will perhaps shut down because corosync does not have enough votes.
In my experience of Cluster 2nodes in PVE5.3 without qdev I have to set exceptionally corosync expeted vote to "1" before invoque delnode.
Is it useless with PVE6.2 ?
 

aaron

Proxmox Staff Member
Staff member
Jun 3, 2019
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Once the node is alone, expected votes should be 1 since it is the only node in the cluster. If you use HA it is a good idea to stop the HA services until everything is back to where you want it
Code:
systemctl stop pve-ha-lrm
systemctl stop pve-ha-crm
 

auranext

Active Member
Jun 5, 2018
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hum , sorry I m back (one more time !)
I m testing removing one node and I need a little clarification at this step
  • first remove the qdevice: pvecm qdevice remove
  • the command need to be executed on all the cluster nodes ? or just the node that is to be reinstalled ?
 

aaron

Proxmox Staff Member
Staff member
Jun 3, 2019
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no, should be enough to run on one node. Compare the output of pvecm status before and after. The qdevice will still be listed, but will not have a vote and the overall number of expected votes should also be down.
 

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