VM Affinity

[skwal]

Hello

In Proxmox 8.2 is there a way to set up affinity between two virtual machines ? The goal is to be sure that two VM are not on the same host.

THX

 

[jsterr]

Hello, you should use ha-groups for that and pin vms to different hosts.
For example: vm1 pinned to host1/2 and vm2 pinned to host 3. or different, depending on what cluster-node-count you have.

 

[bbgeek17]

Hi @skwal , to answer your question - there is no "one-checkmark" built into PVE to achieve your goal.

Given a sufficient number of hosts in the cluster, the solution proposed by @jsterr can work.
However, if the number of nodes is small - then it becomes increasingly harder.

Realistically, with 5 nodes you could:
VM1 - restrict to n1,n2
VM2 - restrict to n3,n4
Manually add/remove n5 on the failure of any one host in group 1 or 2.

You could do 4+qdevice.
With 3 nodes you will need a procedure in place to recover manually after failure.

Sadly, the more reliable approach is an outside script that polls the cluster often and moves VMs around as needed.

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[kmonti]

I created a bash script which helps to avoid situation of place two vms that needs affinity on the same HA group.
https://github.com/kmonticolo/proxmox/blob/master/proxmox_check_vms_tag_ha_group.sh

 

[padot]

I created a bash script which helps to avoid situation of place two vms that needs affinity on the same HA group.
https://github.com/kmonticolo/proxmox/blob/master/proxmox_check_vms_tag_ha_group.sh

pls., be so kindly and replace Polish comments to English for better overview. thx a lot

 

[kmonti]

pls., be so kindly and replace Polish comments to English for better overview. thx a lot

done, thanks for pointing that.