Added host before removing qdevice - what now?

[mgaudette112]

Hi,

I had a 2 host Proxmox cluster with an added qdevice, as is the recommendation with even number of hosts.

I got my hands on a new server and added it to my cluster, naively thinking I would then simply remove the qdevice and get to an even number of nodes, as is the real recommendation.

For reasons that escape me, it seems I cannot do that. This is from the documentation.

Adding/Deleting Nodes After QDevice Setup
If you want to add a new node or remove an existing one from a cluster with a QDevice setup, you need to remove the QDevice first. After that, you can add or remove nodes normally. Once you have a cluster with an even node count again, you can set up the QDevice again as described above.

How do I now delete the qdevice? I have a few older servers I can use temporarily to get to the state I want, but reading the above literally I can't:

1) I can't I simply remove the qdevice
2) I can't add a 4th host and then remove the qdevice
3) I can't remove the newly added node and then remove the qdevice.

I don't believe for a second there is no solution to this and I'm stuck with a qdevice forever hanging over my head.

Thank you for sharing your expertise

 

[waltar]

A QDevice can be removed at any time with the command (the package corosync-qdevice don't need to be deinstalled):
pvecm qdevice remove
and it can be reinstaled with: pvecm qdevice setup <QDEVICE-IP> -f
Check after with the cmd's:
pvecm status
cat /etc/pve/corosync.conf
At the end you should have recommended odd number of pve nodes (3, 5 or 7 ..., regardless if with or without a qdevice running).

 

[mgaudette112]

At the end you should have recommended odd number of pve nodes (3, 5 or 7 ..., regardless if with or without a qdevice running).

I was about to do that, but then why the warning about absolutely removing the qdevice BEFORE adding the node (as quoted in my original poste from the Proxomox docs)

 

[waltar]

The "problem" is that in a cluster with a qdevice each normal pve node needs the additional package corosync-qdevice which isn't installed by default onto a new node which wanted to be a member of an existing cluster which could/would take then config problems by joining. So now you end up with a node without that while the others think about that ... where's the warning about. But nevertheless it's this now and maybe "remove" cmd hopefully just give an error without failing itself by doing so. Otherwise need some editor in the mentioned corosync.conf with a new config_version before savong.

 

[mgaudette112]

The "problem" is that in a cluster with a qdevice each normal pve node needs the additional package corosync-qdevice which isn't installed by default onto a new node which wanted to be a member of an existing cluster which could/would take then config problems by joining. So now you end up with a node without that while the others think about that ... where's the warning about. But nevertheless it's this now and maybe "remove" cmd hopefully just give an error without failing itself by doing so. Otherwise need some editor in the mentioned corosync.conf with a new config_version before savong.

Very clearly explained, thank you.