[SOLVED] Destroying a cluster, leaving one node

[Proximate]

Solved using comment #2 suggestion.

After upgrading from 7.1.7 to 7.2.x, I started having problems. Whether or not I broke something is not the question, I'm sure I did something wrong or at least will blame myself. However, I'm stuck in a whack-a-mole situation of ssh being broken across nodes. I have another post going about that and am not interested in fixing it, I would just like to cleanly re-start.

I would like to take the cluster apart then do a clean install of 7.2 on all four hosts.
I've moved all guests to one host and would like to destroy the cluster so that I can re-install the other three nodes then re-create the cluster.

What I cannot find or perhaps confirm in https://pve.proxmox.com/pve-docs/pve-admin-guide.html#chapter_pvecm are the following.

Once destroyed, what should I clean up on the last host so that no remnants of the previous cluster remain to potentially cause issues when I re-create the cluster. Are there some files/directories, commands I should run so I am starting with a clean slate?

Since the last node was also an upgrade, it seems that I won't end up with a perfectly clean setup.
Yet if I use a node that was re-installed using 7.2 rather than upgraded, it will still have some cluster details left on it.

How I do cleanly destroy the cluster now that I'm down to one host with all the guests on it?

 

[bbgeek17]

If I were you, I would backup VMs to some external host, save any config you think you might need (IPs, names, etc).
Wipe all nodes clean and start from scratch.
If this was any sort of "must keep uptime" situation: build new cluster on the 3 nodes, ensure it works and tested, migrate VMs (backup/restore) from remaining node, wipe/reinstall/join the last node.

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[Proximate]

Yes, these are production guests that cannot be turned off so I'm already taking chances by having them all on one host for this.
That said, they are mainly redundant servers but still part of production as I need a 'real' situation to start using/testing proxmox.

That's an interesting idea, to start a new cluster.

As far as I can tell, the only command required to remove a node is
# pvecm delnode xxx

However I've read that it's also a good idea to remove all removed nodes from any left over nodes in /etc/pve/nodes/<nodename> as well.
Then
# service pve-cluster restart

I've only ever used a cluster, I've not used proxmox hosts stand alone.

Can I migrate the guests over to the new cluster without joining the last remaining node into the new cluster?

 

[bbgeek17]

There is no automatic or live migration between two isolated clusters, or a cluster and standalone node. It will need to be some sort of offline move with downtime.
Considering the history of your old cluster I would pick that route.

For the original request, you can follow steps as described here: https://forum.proxmox.com/threads/proxmox-ve-6-removing-cluster-configuration.56259/
How they will apply to your particular situation is unpredictable.

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[Proximate]

Sorry, not asking about automated or live migration, just if there was a way to migrate even with guest shutdown from one host to a cluster.
You say no above so that answers that. Yes, I could back the guests up to network storage and move them over. There aren't too many.

Thank you. This gives me a nice way to get to a clean setup again.

 

[Proximate]

I guess I should ask one more thing to be sure .

You mentioned no way to migrate from cluster to cluster but I'll have one remaining node/host and one new host before I create another cluster.
Is there a way to migrate guests from host to host before I create the new cluster is will the remaining node still think it's a cluster and this would not work either?

 

[bbgeek17]

Assisted VM migration, ie via PVE tools/GUI is only possible within a cluster. Everything else requires either external backup host or deep understanding of the PVE structure.

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[Proximate]

No problem, I'll use network storage. Just wondered if there was a way to copy guests directly from one host to another where there isn't a cluster.

Thanks for your help.

 

[Proximate]

That worked nicely and now have a nice fresh new cluster. Thank you.