Setting up a cluster with only 2 hosts

[Thechaser]

Hi all,

If I set up a cluster with only two hosts, everyting crashed when one host fails. Can't use cli or even remove the dead node from the cluster.
I wonder what modifications I need to do on the system to get it running on only two hosts and not crash when one fails.

This is a production at home use. that's why I only have two nodes and not three.

Thank you

 

[bbgeek17]

https://forum.proxmox.com/threads/2...:text=You need at least 3 hosts for a cluster.

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

 

[cheiss]

Hi,

first of, I'd suggest you read the chapter on Cluster Management in our admin guide. This explains the basics and what to be aware of when running clusters very well.

If I set up a cluster with only two hosts, everyting crashed when one host fails.

Two-node clusters are not support, see the link above. You can work around that using an external QDevice.

 

[Thechaser]

Thank you both for the information.
I will read it (doing it at the moment).

Maybe its important to note that I don't want to use this cluser for HA. but only for easy migration of a vm from one node to another.
and to mange both in one gui.
so maybe a cluster is not the right method?

If no other solution I will buy a extra node.

 

[spirit]

if you only have 2 nodes,
you need to use CLI to move vms. (it's not possible with gui).


when a node crash:

1) verify that the node is really crashed and vms are not running anymore

2) on the other node : #pvecm expected 1 (to be able to write in /etc/pve )

3) on the other node : #mv /etc/pve/nodes/<crashednode>/qemu-server/* /etc/pve/nodes/<othernodes>qemu-server/

then start all vms on the other node with gui



if you have a third node. (could be a small nuc , without any vms running on it), you could enable HA and the failover done automatically)

 

[Thechaser]

if you only have 2 nodes,
you need to use CLI to move vms. (it's not possible with gui).


when a node crash:

1) verify that the node is really crashed and vms are not running anymore

2) on the other node : #pvecm expected 1 (to be able to write in /etc/pve )

3) on the other node : #mv /etc/pve/nodes/<crashednode>/qemu-server/* /etc/pve/nodes/<othernodes>qemu-server/

then start all vms on the other node with gui



if you have a third node. (could be a small nuc , without any vms running on it), you could enable HA and the failover done automatically)

Hello,

Thank you for this information.
Your reply was giving me the solution I needed I think.
If I set up my cluser with 2 server + small nuc to have three nodes and only start the nuc when one fails I assume the gui will kick in when the nuc is up and running.

I have read the other links that where provided, and they have given me indeed more information.

thank you all