cluster: mix PVE 7 & 8

[PaulVM]

I have a PVE 7.x cluster with 3 nodes (2 PVE with VM/CT + 1 PVE/PBS).
No ceph.
I want to add 3 new PVE 8.x nodes where to install also ceph and when it is ready move the VMs from the old PVE 7.x nodes that will be dismissed (the PBS updated).
Can I mix 7.x and 8.x?

Thanks, P.

 

[Maximiliano]

Yes you can, but I would highly discourage keeping the cluster in this state for a sustained period.

Do note that migrating VMs from older to newer versions is supported but the other way around is not, even though it might work in many setups. Another thing to keep in mind is that the web UI of a node running an older version might fail to display certain properties of nodes running newer versions, you should use the web UI of a updated node.

 

[robertut]

I was in the same boat, yes, and upgrade/node addition worked fine this way.

 

[PaulVM]

Now that I am at implementing the new nodes, I evaluated that my final goal is to have a 8.x cluster that have 3 new nodes (with ceph), and the only interesting things that I need to insert/mantain in the new cluster from the old (apart VM & CT), are the firewall rules and the PBS host.
For the firewall rules, I noticied that simply copying the /etc/pve/firewall folder solve the problem.
Move the VM & CT isn't a problem (I can have some downtime).
Is the migration of the PBS node from old cluster to a new cluster big issue like it seems from the documentation?
I suppose that start with a new cluster is better that add 3 new nodes to the old and then remove 2 old nodes.

Thanks, P.

 

[sbudhi]

how about this scheme:
1. existing cluster A with 3server (node1-2-3) PVE7+CEPH
2. add new 2server (node4-5) PVE8+CEPH to cluster A
3. migrate all VM within node1-2-3 to new node4-5
4. remove node1, reinstall server node1 w/PVE8+CEPH & rejoin to cluster A
5. also same method-4 for node2-3
are those step will working fine?

 

[LnxBil]

are those step will working fine?

Why do you need to add new nodes? Your cluster should be able to run everything on just two out of three nodes, isn't it?
A PVE update does not take more than 30 minutes per node (excluding migrating VMs).

 

[sbudhi]

Why do you need to add new nodes? Your cluster should be able to run everything on just two out of three nodes, isn't it?
A PVE update does not take more than 30 minutes per node (excluding migrating VMs).

we're planning to add more VM that required more server/nodes, beside future CEPH change setting preparing in case one node down, still one spare (kind of raid-6 with 1parity+1spare)
beside those also current cluster still running VM that serves many customer, just take precautions in case failure upgrade. our current PVE version 7.2-11

 

[LnxBil]

we're planning to add more VM that required more server/nodes, beside future CEPH change setting preparing in case one node down, still one spare (kind of raid-6 with 1parity+1spare)
beside those also current cluster still running VM that serves many customer, just take precautions in case failure upgrade. our current PVE version 7.2-11

Thank you for explaining.