How 4 nodes cluster vm are still running when 2 nodes

T

Taufik Hidayat

New Member
Aug 20, 2018
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Hello,
I have 4 nodes cluster with the same server specifications.
when 2 nodes die, 2 other nodes are still running (after restarting themselves) but the vm does not run, with the statement "waiting for quorum".
is there a way that when 2 nodes die can be handled by 2 other nodes so that vm keeps running?

Thank you
 
Hi!

The quorum is provided by more than half of votes.
For a 4-node cluster, this is 4/2 + 1 = 3.
You have 2 nodes left. The quorum is not provided.

Best regards,
Gosha
 
Hi!

To run the VMs, you must provide a quorum. You do not have a quorum.
The 4-node cluster is not profitable to do because the quorum is more than half the votes - to ensure the operation of the 4-node cluster you need 3 working nodes.

If you look at a 3-node cluster, then it needs 2 working nodes.
I do not know - it's possible to delete one node from cluster in your case?
If this is done, the cluster will become a 3-node cluster (with a quorum of 2) and then this will ensure the start of the VMs.

Gosha
 
Last edited:
And if you need your 4 nodes for load/performance, you can still add a 5th "light" node in order to have an odd number for the quorum.
It can be a simple Raspberry Pi https://pve.proxmox.com/wiki/Raspberry_Pi_as_third_node or a small VM running Proxmox outside of your 4 nodes cluster (of course).
I've used both, the RPI and Proxmox VM hosted on one of my NAS (phpVirtualbox) without issue.
 
gosha said:
Hi!

To run the VMs, you must provide a quorum. You do not have a quorum.
The 4-node cluster is not profitable to do because the quorum is more than half the votes - to ensure the operation of the 4-node cluster you need 3 working nodes.

If you look at a 3-node cluster, then it needs 2 working nodes.
I do not know - it's possible to delete one node from cluster in your case?
If this is done, the cluster will become a 3-node cluster (with a quorum of 2) and then this will ensure the start of the VMs.

Gosha
Click to expand...

if deleted it might be even more complicated to build it because I use gulster.
btw thank you for your answer Gosha :D

Belokan said:
And if you need your 4 nodes for load/performance, you can still add a 5th "light" node in order to have an odd number for the quorum.
It can be a simple Raspberry Pi https://pve.proxmox.com/wiki/Raspberry_Pi_as_third_node or a small VM running Proxmox outside of your 4 nodes cluster (of course).
I've used both, the RPI and Proxmox VM hosted on one of my NAS (phpVirtualbox) without issue.
Click to expand...

wow thanks a lot for the solution, belokan.
Is it possible if I use a mini PC? or maybe using vm on another cluster node? : 3
 
Yes, the "witness" (only used for quorum) can be a mini PC installed with PM and added to the cluster or a VM. But for obvious reason, the VM bas to be located outside of the cluster its supposed to provide quorum to.
 
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