2 HA Host one node done. How to move VM ?

[Badkey]

Dear all,

I have a 2 node HA Cluster. One is down but there is still a (stopped) VM on it. How can I move this VM to the active Node ?
The cluster is using a NFS share there is also the data of the VM.



Thanks in advance voor the respond.

Regards John

 

[aaron]

A PVE Cluster works on the quorum/majority principle. Each node has one vote. A two node cluster is a special situation. If one node is down, you only have 50% of the votes and therefore no majority. This means that certain actions cannot be done like starting a VM or changing the config of a VM. The recommendation is to always have an odd number of nodes in a cluster to avoid a "split brain" situation in which it is not certain if the other half is still up or not.

If you cannot add a third node to the cluster, you can use the QDevice mechanism which provides one more vote to the cluster. You would end up with 3 votes in total and would still have 2 votes if one node is down.

You will need to install the corosync-qnetd service on another machine that is external to the PVE cluster. That could even be a raspberry pie board. Then install the corosync-qdevice packets on the PVE nodes and set up the QDevice. There is a chapter in the PVE admin guide explaining the whole procedure.

 

[Badkey]

Ok. But now one node is down (defect) but still I see a stopt VM how do I move is manualy to the node that is Up ?

 

[ermanishchawla]

For VM to move to another node ( ie node which is up) VM must use the shared storage. if VM is already on shared storage
do pvecm expected 1 and then migrate

 

[Badkey]

Yep. The cluster is using a NFS share there is also the data of the VM. I can see the data.

But how to move the Node has a defect power supply that is why.

Regards John

 

[ermanishchawla]

Step 1 : pvecm expected 1
Step 2 : Copy /etc/pve/nodes/<failednode>/qemu-server/*.conf to /etc/pve/nodes/<active-node>/qemu-server/*.conf

failednode = Node hostname which has failed
Active-node= Node hostname where you want to move