Maintaining 2-Node Quorum

[Grunt]

I'm downsizing my proxmox cluster from 7 physical nodes to 2. I just wanted to make sure what I am doing is "supported" and "best practice". I quoted those two phrases because I'm aware that a 2-node cluster is not recommended/suggested.

• I edited my corosync config to give one of my 2-nodes an additional vote. Thus, when I am down to two nodes, a quorum can be maintained, correct?
• If either of my two nodes goes down, will the VMs in the node that is up continue to function?
• When a single node is running, can HA still function and all the VMs configured for HA that were on the failed node, startup on the running node (assuming resources are available)?

 

[genguser]

Hi, im not the expert but what i knows is the cluster cannot be in OK state when u have running less than 1/2 votes of whole cluster nodes. So i guess when your node with incremented vote will fail then your cluster wil fail also.
But i have pretty simillar setup i have currently set two nodes plus RPi as corosync qdevice. Mine configuration is as i have only one of nodes running except rpi. The second is almost all the time turned off and purpose is only as backup for data and auto redundancy for VM/CT due to electricity cost.
So, if RPi has 2 votes, and two other nodes has each 1 vote, then if i have running one node, than i have 3 votes, if both, than i have 4 votes and so on. That also have some downsides, i have to trust raspberry more than other devices. but as i'm using it just for monitoring, then i'm actually calm.
I'm pretty sure mine setup is not recommended, but in my configuration it is working pretty stable.

 

[fabian]

if you only have two real nodes, please setup a qdevice as tie-breaker. then HA (provided the other requisites for HA are met, like no local resources) and the remaining node will work if one of the real nodes go down. there is no need to mess with the vote weights, nor is there any advantage in doing so.