how to reinstall node in cluster Two nodes with quorum device

auranext

Well-Known Member
Jun 5, 2018
53
2
48
123
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
 
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 :)
 
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 ?
 
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
 
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 ?
 
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.
 
Hi,
@aaron I've tested the procedure and there is an inconsistency
  • 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
I encounter a pb at the step "Remove the one node following the guide https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_remove_a_cluster_node"
The procedure say after poweredoff the node execute pvecm delnode <node> on the other node.
But the quorum is not established because the node is alone, expected votes is 2...
So can I exec the delnode command when the 2 nodes are powered on ?
 
Oh true.
In that case, the best approach is probably to set the expected votes to 1 manually. In a larger cluster, this is usually not a problem. I will see how we can mention that in the docs.

Code:
pvecm expected 1
 
Hi,
I have checked the delnode procedure and here is the results

root@FLEXCLIPVE03:~# pvecm delnode FLEXITXPVE03
Could not kill node (error = CS_ERR_NOT_EXIST)
Killing node 2
command 'corosync-cfgtool -k 2' failed: exit code 1


It seems that FLEXITXPVE03 node has been removed in other way...
How I can be totally sure that the node has been removed ?
and how I can validate the procedure ?


STEP BY STEP DETAILED :

root@FLEXCLIPVE03:~# pvecm status
Cluster information
-------------------
Name: cluster3
Config Version: 4
Transport: knet
Secure auth: on

Quorum information
------------------
Date: Wed Nov 23 21:15:42 2022
Quorum provider: corosync_votequorum
Nodes: 1
Node ID: 0x00000001
Ring ID: 1.108
Quorate: No

Votequorum information
----------------------
Expected votes: 2
Highest expected: 2
Total votes: 1
Quorum: 2 Activity blocked
Flags: Qdevice

Membership information
----------------------
Nodeid Votes Qdevice Name
0x00000001 1 NA,NV,NMW 192.168.103.1 (local)
0x00000000 0 Qdevice (votes 0)




root@FLEXCLIPVE03:~# pvecm expected 1
root@FLEXCLIPVE03:~# echo $?
0
root@FLEXCLIPVE03:~# pvecm status
Cluster information
-------------------
Name: cluster3
Config Version: 4
Transport: knet
Secure auth: on

Quorum information
------------------
Date: Wed Nov 23 21:21:31 2022
Quorum provider: corosync_votequorum
Nodes: 1
Node ID: 0x00000001
Ring ID: 1.108
Quorate: Yes

Votequorum information
----------------------
Expected votes: 1
Highest expected: 1
Total votes: 1
Quorum: 1
Flags: Quorate Qdevice

Membership information
----------------------
Nodeid Votes Qdevice Name
0x00000001 1 NA,NV,NMW 192.168.103.1 (local)
0x00000000 0 Qdevice (votes 0)

root@FLEXCLIPVE03:~# pvecm delnode FLEXITXPVE03
Could not kill node (error = CS_ERR_NOT_EXIST)
Killing node 2
command 'corosync-cfgtool -k 2' failed: exit code 1
 
Last edited:

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!