What happen when a member cluster is down ?

[rpereyra]

Hi

What happen when a member cluster is down ?

I have two pm servers in cluster mode just configured.

I wonder what happen when a member node is down

If I restart an online member, vms start without any issue ?

I saw in this forum some issues with clusters when one node is offline.

thanks

roberto

 

[fabian]

in a two node cluster you lose quorum when either node is down. without quorum, the cluster file system used to store /etc/pve is read-only, so you cannot modify, start, .. anything. you need at least three nodes for your cluster to remain quorate in case one node goes down (5 nodes to "survive" 2 nodes going down, 2n+1 to survive n nodes going down)

 

[rpereyra]

Hi Fabian

Thanks a lot for your reply.

So it is not advisable to create a cluster with only two nodes?

roberto

 

[fabian]

if you know about the limitations, it's perfectly okay to run a two node cluster (the main advantage is the shared management interface and ability to easily migrate from one node to the other). just don't expect HA or any kind of failover to work automatically.

 

[rpereyra]

Thanks Fabian

roberto